| Transactions |
| Date | Team | Player | Type | OthTm | EffDate | When |
| 4/5/2010 | ATL | Tazawa | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Choate | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Dukes | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Figaro | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Figueroa | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Hairston | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Johnson | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Kinsler | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Maxwell | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Miller | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Owings | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Parmelee | Demoted to reserve roster | | | Before |
| 4/5/2010 | FLA | Peguero | Demoted to reserve roster | | | Before |
| 4/5/2010 | NYN | Rzepczynski | Demoted to reserve roster | | | Before |
| 4/5/2010 | PIT | Getz | Demoted to reserve roster | | | Before |
| 4/5/2010 | PIT | Rosales | Promoted to active roster | | | Before |
| 4/7/2010 | WAS | Aceves | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Beltran | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Bianchi | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Buchholz | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Farquhar | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Gathright | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Guthrie | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Hill | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Ohlendorf | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Pucetas | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Salazar | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Timmons | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Venable | Demoted to reserve roster | | | Before |
| 4/7/2010 | WAS | Walden | Demoted to reserve roster | | | Before |
| 4/8/2010 | CIN | Bailey | Demoted to reserve roster | | | Before |
| 4/8/2010 | CIN | Maholm | Promoted to active roster | | | Before |
| 4/8/2010 | PIT | Jakubauskas | Traded away | DET | | After |
| 4/9/2010 | CHN | Parr | Promoted to active roster | | | Before |
| 4/9/2010 | CHN | Paulino | Demoted to reserve roster | | | Before |
| 4/9/2010 | CHN | Paulino | Promoted to active roster | | | Before |
| 4/9/2010 | CHN | Wells | Demoted to reserve roster | | | Before |
| 4/9/2010 | CIN | Seay | Released | | | Before |
| 4/9/2010 | NYN | Guillen | Released | | | Before |
| 4/9/2010 | NYN | Redmond | Signed | | | Before |
| 4/9/2010 | SD | Giles | Released | | | Before |
| 4/9/2010 | WAS | Stammen | Signed | | | Before |
| 4/12/2010 | ARI | Gervacio | Demoted to reserve roster | | | Before |
| 4/12/2010 | ARI | Pelfrey | Promoted to active roster | | | Before |
| 4/12/2010 | COL | Jackson | Promoted to active roster | | | Before |
| 4/12/2010 | COL | Saltalamacchia | Demoted to reserve roster | | | Before |
| 4/12/2010 | NYN | Johnson | Demoted to reserve roster | | | Before |
| 4/12/2010 | NYN | Redmond | Promoted to active roster | | | Before |
| 4/12/2010 | NYN | Sanchez | Promoted to active roster | | | Before |
| 4/12/2010 | STL | Clippard | Promoted to active roster | | | Before |
| 4/12/2010 | STL | Freeman | Promoted to active roster | | | Before |
| 4/12/2010 | STL | Koplove | Demoted to reserve roster | | | Before |
| 4/12/2010 | STL | Overbay | Demoted to reserve roster | | | Before |
| 4/14/2010 | PIT | Getz | Demoted to reserve roster | | | Before |
| 4/14/2010 | PIT | Rosales | Promoted to active roster | | | Before |
| 4/15/2010 | MIL | Montero | Demoted to reserve roster | | | Before |
| 4/16/2010 | PIT | Mientkiewicz | Released | | | Before |
| 4/16/2010 | STL | Bloomquist | Demoted to reserve roster | | | Before |
| 4/16/2010 | STL | Downs | Promoted to active roster | | | Before |
| 4/18/2010 | COL | Glaus | Acquired via trade | SF | | After |
| 4/18/2010 | COL | Pence | Traded away | SF | | After |
| 4/18/2010 | COL | Victorino | Acquired via trade | SF | | After |
| 4/18/2010 | SF | Glaus | Traded away | COL | | After |
| 4/18/2010 | SF | Pence | Acquired via trade | COL | | After |
| 4/18/2010 | SF | Victorino | Traded away | COL | | After |
| 4/19/2010 | ARI | Pie | Demoted to reserve roster | | | Before |
| 4/19/2010 | ARI | Runzler | Promoted to active roster | | | Before |
| 4/19/2010 | CHN | Wells | Promoted to active roster | | | Before |
| 4/19/2010 | CHN | Young | Demoted to reserve roster | | | Before |
| 4/19/2010 | MIL | Wood | Promoted to active roster | | | Before |
| 4/19/2010 | PHI | Sogard | Released | | | Before |
| 4/19/2010 | PIT | Buck | Promoted to active roster | | | Before |
| 4/19/2010 | PIT | Gomez | Released | | | Before |
| 4/19/2010 | PIT | Hill | Released | | | Before |
| 4/19/2010 | PIT | Monasterios | Released | | | Before |
| 4/19/2010 | PIT | Shoppach | Demoted to reserve roster | | | Before |
| 4/19/2010 | SF | Ascanio | Signed | | | Before |
| 4/19/2010 | SF | Gregg | Promoted to active roster | | | Before |
| 4/19/2010 | SF | Hill | Demoted to reserve roster | | | Before |
| 4/19/2010 | SF | Manzella | Promoted to active roster | | | Before |
| 4/19/2010 | SF | Skelton | Released | | | Before |
| 4/19/2010 | STL | Headley | Demoted to reserve roster | | | Before |
| 4/19/2010 | STL | McGehee | Promoted to active roster | | | Before |
| 4/19/2010 | WAS | Eveland | Signed | | | Before |
| 4/19/2010 | WAS | Stammen | Released | | | Before |
| 4/20/2010 | PHI | Roberts | Demoted to reserve roster | | | Before |
| 4/20/2010 | PIT | Crosby | Released | | | Before |
| 4/20/2010 | PIT | Crosby | Signed | | | Before |
| 4/21/2010 | PHI | Narveson | Promoted to active roster | | | Before |
| 4/21/2010 | SD | Fuentes | Demoted to reserve roster | | | Before |
| 4/22/2010 | ARI | Fox | Traded away | DET | | After |
| 4/22/2010 | ARI | Gaub | Acquired via trade | DET | | After |
| 4/22/2010 | CIN | Arroyo | Traded away | ANA | | After |
| 4/22/2010 | CIN | Jones | Acquired via trade | ANA | | After |
| 4/23/2010 | ARI | Hessman | Signed | | | Before |
| 4/23/2010 | ARI | Hessman | Promoted to active roster | | | Before |
| 4/23/2010 | ARI | Pelfrey | Demoted to reserve roster | | | Before |
| 4/23/2010 | CIN | Blackmon | Demoted to reserve roster | | | Before |
| 4/23/2010 | CIN | del Rosario | Promoted to active roster | | | Before |
| 4/23/2010 | CIN | Kennedy | Demoted to reserve roster | | | Before |
| 4/23/2010 | CIN | Mientkiewicz | Signed | | | Before |
| 4/23/2010 | CIN | Parra | Promoted to active roster | | | Before |
| 4/23/2010 | HOU | Bray | Demoted to reserve roster | | | Before |
| 4/23/2010 | HOU | Mathis | Promoted to active roster | | | Before |
| 4/23/2010 | MIL | Johnson | Released | | | Before |
| 4/23/2010 | MIL | Schneider | Signed | | | Before |
| 4/23/2010 | MIL | Schneider | Promoted to active roster | | | Before |
| 4/23/2010 | MIL | Wood | Demoted to reserve roster | | | Before |
| 4/23/2010 | PIT | Jacobs | Released | | | Before |
| 4/23/2010 | PIT | Jacobs | Released | | | Before |
| 4/23/2010 | PIT | Jacobs | Signed | | | Before |
| 4/23/2010 | PIT | Jacobs | Signed | | | Before |
| 4/23/2010 | SF | Silva | Signed | | | Before |
| 4/23/2010 | STL | Venters | Signed | | | Before |
| 4/26/2010 | ARI | Belisario | Promoted to active roster | | | Before |
| 4/26/2010 | ARI | Bernadina | Signed | | | Before |
| 4/26/2010 | ARI | Bernadina | Promoted to active roster | | | Before |
| 4/26/2010 | ARI | Fister | Signed | | | Before |
| 4/26/2010 | ARI | Gaub | Demoted to reserve roster | | | Before |
| 4/26/2010 | ARI | Gervacio | Promoted to active roster | | | Before |
| 4/26/2010 | ARI | Kilby | Demoted to reserve roster | | | Before |
| 4/26/2010 | ARI | Runzler | Demoted to reserve roster | | | Before |
| 4/26/2010 | ATL | Gordon | Promoted to active roster | | | Before |
| 4/26/2010 | ATL | Kazmir | Promoted to active roster | | | Before |
| 4/26/2010 | ATL | Marte | Demoted to reserve roster | | | Before |
| 4/26/2010 | CIN | del Rosario | Demoted to reserve roster | | | Before |
| 4/26/2010 | CIN | Mientkiewicz | Released | | | Before |
| 4/26/2010 | CIN | Roemer | Signed | | | Before |
| 4/26/2010 | CIN | Thatcher | Promoted to active roster | | | Before |
| 4/26/2010 | COL | Hearne | Promoted to active roster | | | Before |
| 4/26/2010 | COL | Ishikawa | Released | | | Before |
| 4/26/2010 | COL | Marquis | Demoted to reserve roster | | | Before |
| 4/26/2010 | HOU | Bush | Promoted to active roster | | | Before |
| 4/26/2010 | HOU | Jackson | Demoted to reserve roster | | | Before |
| 4/26/2010 | HOU | Kalish | Promoted to active roster | | | Before |
| 4/26/2010 | HOU | Young | Demoted to reserve roster | | | Before |
| 4/26/2010 | MIL | Burton | Demoted to reserve roster | | | Before |
| 4/26/2010 | MIL | Meek | Promoted to active roster | | | Before |
| 4/26/2010 | NYN | Kuo | Promoted to active roster | | | Before |
| 4/26/2010 | NYN | Manuel | Demoted to reserve roster | | | Before |
| 4/26/2010 | PIT | Hughes | Released | | | Before |
| 4/26/2010 | PIT | Hughes | Signed | | | Before |
| 4/26/2010 | PIT | Jacobs | Signed | | | Before |
| 4/26/2010 | PIT | Nix | Released | | | Before |
| 4/26/2010 | SD | Thompson | Signed | | | Before |
| 4/26/2010 | STL | Collins | Promoted to active roster | | | Before |
| 4/26/2010 | STL | Manning | Demoted to reserve roster | | | Before |
| 4/26/2010 | WAS | Mathis | Demoted to reserve roster | | | Before |
| 4/26/2010 | WAS | Timmons | Promoted to active roster | | | Before |
| 4/27/2010 | LAD | Lilly | Promoted to active roster | | | Before |
| 4/27/2010 | LAD | Pavano | Demoted to reserve roster | | | Before |
| 4/27/2010 | PHI | Narveson | Demoted to reserve roster | | | Before |
| 4/27/2010 | PHI | Romero | Promoted to active roster | | | Before |
| 4/29/2010 | CIN | Lopez | Traded away | KC | | After |
| 4/30/2010 | ARI | Brown | Signed | | | Before |
| 4/30/2010 | ARI | Brown | Promoted to active roster | | | Before |
| 4/30/2010 | ARI | Gaub | Released | | | Before |
| 4/30/2010 | ARI | Gervacio | Demoted to reserve roster | | | Before |
| 4/30/2010 | CIN | Breslow | Demoted to reserve roster | | | Before |
| 4/30/2010 | CIN | Martinez | Signed | | | Before |
| 4/30/2010 | CIN | Roemer | Released | | | Before |
| 4/30/2010 | CIN | Westbrook | Promoted to active roster | | | Before |
| 4/30/2010 | COL | Littleton | Demoted to reserve roster | | | Before |
| 4/30/2010 | FLA | Benoit | Demoted to reserve roster | | | Before |
| 4/30/2010 | FLA | de la Rosa | Demoted to reserve roster | | | Before |
| 4/30/2010 | FLA | Hairston | Promoted to active roster | | | Before |
| 4/30/2010 | FLA | Johnson | Promoted to active roster | | | Before |
| 4/30/2010 | FLA | Maxwell | Demoted to reserve roster | | | Before |
| 4/30/2010 | FLA | Maxwell | Promoted to active roster | | | Before |
| 4/30/2010 | FLA | Maxwell | Promoted to active roster | | | Before |
| 4/30/2010 | FLA | McGowan | Demoted to reserve roster | | | Before |
| 4/30/2010 | FLA | Owings | Promoted to active roster | | | Before |
| 4/30/2010 | FLA | Peguero | Promoted to active roster | | | Before |
| 4/30/2010 | FLA | Ray | Demoted to reserve roster | | | Before |
| 4/30/2010 | FLA | Wheeler | Demoted to reserve roster | | | Before |
| 4/30/2010 | MIL | Doolittle | Released | | | Before |
| 4/30/2010 | MIL | Embree | Signed | | | Before |
| 4/30/2010 | NYN | Chavez | Demoted to reserve roster | | | Before |
| 4/30/2010 | PHI | Motte | Demoted to reserve roster | | | Before |
| 4/30/2010 | PHI | Motte | Promoted to active roster | | | Before |
| 4/30/2010 | PHI | Speier | Released | | | Before |
| 4/30/2010 | PHI | Vargas | Signed | | | Before |
| 4/30/2010 | PIT | Hughes | Released | | | Before |
| 4/30/2010 | PIT | Hughes | Signed | | | Before |
| 4/30/2010 | PIT | Jacobs | Released | | | Before |
| 4/30/2010 | PIT | Jacobs | Signed | | | Before |
| 4/30/2010 | PIT | Rodriguez | Released | | | Before |
| 4/30/2010 | PIT | Rodriguez | Signed | | | Before |
| 4/30/2010 | SF | Simon | Signed | | | Before |
| 4/30/2010 | STL | Headley | Promoted to active roster | | | Before |
| 4/30/2010 | STL | Manning | Released | | | Before |
| 4/30/2010 | STL | McGehee | Demoted to reserve roster | | | Before |
| 4/30/2010 | WAS | Atilano | Signed | | | Before |
| 4/30/2010 | WAS | Hill | Released | | | Before |
| 5/2/2010 | ARI | Capps | Acquired via trade | ANA | | After |
| 5/2/2010 | ARI | DeJesus | Acquired via trade | ANA | | After |
| 5/2/2010 | ARI | Flowers | Traded away | ANA | | After |
| 5/2/2010 | ARI | Kuroda | Acquired via trade | ANA | | After |
| 5/2/2010 | ARI | McGee | Traded away | ANA | | After |
| 5/2/2010 | ARI | Viciedo | Traded away | ANA | | After |
| 5/3/2010 | ARI | Bernadina | Released | | | Before |
| 5/3/2010 | ARI | Brown | Demoted to reserve roster | | | Before |
| 5/3/2010 | ARI | Chirinos | Signed | | | Before |
| 5/3/2010 | ARI | Davis | Demoted to reserve roster | | | Before |
| 5/3/2010 | ARI | Gervacio | Released | | | Before |
| 5/3/2010 | ARI | McDonald | Signed | | | Before |
| 5/3/2010 | ARI | McDonald | Promoted to active roster | | | Before |
| 5/3/2010 | ARI | Takahashi | Demoted to reserve roster | | | Before |
| 5/3/2010 | CHN | Hammel | Demoted to reserve roster | | | Before |
| 5/3/2010 | CHN | Paulino | Promoted to active roster | | | Before |
| 5/3/2010 | FLA | Kinsler | Promoted to active roster | | | Before |
| 5/3/2010 | FLA | Maxwell | Demoted to reserve roster | | | Before |
| 5/3/2010 | NYN | Johnson | Promoted to active roster | | | Before |
| 5/3/2010 | PHI | Garcia | Promoted to active roster | | | Before |
| 5/3/2010 | PHI | Madson | Demoted to reserve roster | | | Before |
| 5/3/2010 | PIT | Fulchino | Promoted to active roster | | | Before |
| 5/3/2010 | PIT | Gervacio | Released | | | Before |
| 5/3/2010 | PIT | Gervacio | Signed | | | Before |
| 5/3/2010 | PIT | Hughes | Signed | | | Before |
| 5/3/2010 | PIT | Jacobs | Released | | | Before |
| 5/3/2010 | PIT | Jakubauskas | Signed | | | Before |
| 5/3/2010 | PIT | Monasterios | Signed | | | Before |
| 5/3/2010 | PIT | Rodriguez | Signed | | | Before |
| 5/3/2010 | PIT | Rosales | Released | | | Before |
| 5/3/2010 | STL | Bloomquist | Promoted to active roster | | | Before |
| 5/3/2010 | STL | Hawpe | Demoted to reserve roster | | | Before |
| 5/5/2010 | ATL | Neshek | Demoted to reserve roster | | | Before |
| 5/5/2010 | WAS | Cruz | Demoted to reserve roster | | | Before |
| 5/6/2010 | WAS | Aceves | Promoted to active roster | | | Before |
| 5/6/2010 | WAS | Carlson | Demoted to reserve roster | | | Before |
| 5/6/2010 | WAS | Venable | Promoted to active roster | | | Before |
| 5/7/2010 | ARI | Brignac | Demoted to reserve roster | | | Before |
| 5/7/2010 | ARI | Davis | Promoted to active roster | | | Before |
| 5/7/2010 | CIN | Bailey | Promoted to active roster | | | Before |
| 5/7/2010 | CIN | Marshall | Demoted to reserve roster | | | Before |
| 5/7/2010 | MIL | Giese | Released | | | Before |
| 5/7/2010 | PHI | Escobar | Released | | | Before |
| 5/7/2010 | PHI | Maier | Signed | | | Before |
| 5/7/2010 | PHI | Maier | Promoted to active roster | | | Before |
| 5/7/2010 | PHI | Miller | Demoted to reserve roster | | | Before |
| 5/7/2010 | PHI | Roenicke | Promoted to active roster | | | Before |
| 5/7/2010 | PHI | Romero | Demoted to reserve roster | | | Before |
| 5/7/2010 | PIT | Gervacio | Signed | | | Before |
| 5/7/2010 | PIT | Gervacio | Promoted to active roster | | | Before |
| 5/7/2010 | PIT | Hughes | Released | | | Before |
| 5/7/2010 | PIT | Mientkiewicz | Signed | | | Before |
| 5/7/2010 | PIT | Mientkiewicz | Demoted to reserve roster | | | Before |
| 5/7/2010 | SF | Hensley | Signed | | | Before |
| 5/7/2010 | WAS | Baker | Demoted to reserve roster | | | Before |
| 5/7/2010 | WAS | Mercado | Signed | | | Before |
| 5/7/2010 | WAS | Mercado | Promoted to active roster | | | Before |
| 5/7/2010 | WAS | Salazar | Released | | | Before |
| 5/9/2010 | CIN | Bailey | Demoted to reserve roster | | | Before |
| 5/9/2010 | CIN | Cooper | Released | | | Before |
| 5/9/2010 | CIN | del Rosario | Promoted to active roster | | | Before |
| 5/9/2010 | CIN | Gillaspie | Released | | | Before |
| 5/9/2010 | CIN | Lecure | Signed | | | Before |
| 5/9/2010 | CIN | Lecure | Demoted to reserve roster | | | Before |
| 5/9/2010 | CIN | Marshall | Promoted to active roster | | | Before |
| 5/9/2010 | CIN | Soto | Signed | | | Before |
| 5/9/2010 | CIN | Soto | Demoted to reserve roster | | | Before |
| 5/9/2010 | CIN | Westbrook | Demoted to reserve roster | | | Before |
| 5/9/2010 | PIT | Beckett | Acquired via trade | NYA | | After |
| 5/9/2010 | PIT | Feliz | Acquired via trade | NYA | | After |
| 5/9/2010 | PIT | Halladay | Traded away | NYA | | After |
| 5/9/2010 | PIT | Papelbon | Acquired via trade | NYA | | After |
| 5/9/2010 | PIT | Stetter | Traded away | NYA | | After |
| 5/9/2010 | PIT | Weathers | Traded away | NYA | | After |
| 5/10/2010 | CHN | Chico | Signed | | | Before |
| 5/10/2010 | CHN | Heether | Released | | | Before |
| 5/10/2010 | CIN | Cooper | Released | | | Before |
| 5/10/2010 | CIN | Gillaspie | Released | | | Before |
| 5/10/2010 | CIN | Lecure | Signed | | | Before |
| 5/10/2010 | CIN | Soto | Signed | | | Before |
| 5/10/2010 | HOU | Schafer | Demoted to reserve roster | | | Before |
| 5/10/2010 | HOU | Schafer | Promoted to active roster | | | Before |
| 5/10/2010 | HOU | Schafer | Demoted to reserve roster | | | Before |
| 5/10/2010 | HOU | Schafer | Promoted to active roster | | | Before |
| 5/10/2010 | PHI | Blanton | Promoted to active roster | | | Before |
| 5/10/2010 | PHI | Garcia | Demoted to reserve roster | | | Before |
| 5/10/2010 | PIT | Cruz | Demoted to reserve roster | | | Before |
| 5/10/2010 | PIT | Getz | Promoted to active roster | | | Before |
| 5/10/2010 | PIT | Johnson | Demoted to reserve roster | | | Before |
| 5/10/2010 | PIT | Kozma | Demoted to reserve roster | | | Before |
| 5/10/2010 | PIT | Kozma | Promoted to active roster | | | Before |
| 5/10/2010 | PIT | Mientkiewicz | Promoted to active roster | | | Before |
| 5/10/2010 | PIT | Taveras | Released | | | Before |
| 5/10/2010 | STL | Hawksworth | Promoted to active roster | | | Before |
| 5/10/2010 | STL | Izturis | Demoted to reserve roster | | | Before |
| 5/10/2010 | STL | Jurrjens | Demoted to reserve roster | | | Before |
| 5/10/2010 | STL | McGehee | Promoted to active roster | | | Before |
| 5/11/2010 | COL | Saltalamacchia | Promoted to active roster | | | Before |
| 5/11/2010 | LAD | Donnelly | Demoted to reserve roster | | | Before |
| 5/11/2010 | LAD | Lowe | Demoted to reserve roster | | | Before |
| 5/11/2010 | LAD | Sanches | Promoted to active roster | | | Before |
| 5/11/2010 | SF | Furcal | Demoted to reserve roster | | | Before |
| 5/11/2010 | SF | Hill | Promoted to active roster | | | Before |
| 5/13/2010 | ARI | Brown | Released | | | Before |
| 5/13/2010 | ARI | Davis | Demoted to reserve roster | | | Before |
| 5/13/2010 | ARI | Takahashi | Promoted to active roster | | | Before |
| 5/13/2010 | CHN | Hammel | Promoted to active roster | | | Before |
| 5/13/2010 | CHN | Ramirez | Promoted to active roster | | | Before |
| 5/13/2010 | CHN | Atkins | Traded away | STL | | After |
| 5/13/2010 | CHN | Headley | Acquired via trade | STL | | After |
| 5/13/2010 | CHN | Olsen | Acquired via trade | STL | | After |
| 5/13/2010 | CHN | Penny | Traded away | STL | | After |
| 5/13/2010 | CIN | del Rosario | Demoted to reserve roster | | | Before |
| 5/13/2010 | CIN | Lecure | Released | | | Before |
| 5/13/2010 | CIN | Konerko | Acquired via trade | ANA | | After |
| 5/13/2010 | CIN | Lewis | Acquired via trade | ANA | | After |
| 5/13/2010 | CIN | Masterson | Traded away | ANA | | After |
| 5/13/2010 | COL | Miller | Signed | | | Before |
| 5/13/2010 | FLA | Bell | Signed | | | Before |
| 5/13/2010 | FLA | Miller | Released | | | Before |
| 5/13/2010 | HOU | Billingsley | Demoted to reserve roster | | | Before |
| 5/13/2010 | MIL | Diaz | Signed | | | Before |
| 5/13/2010 | MIL | Schneider | Released | | | Before |
| 5/13/2010 | PHI | Gonzalez | Signed | | | Before |
| 5/13/2010 | PHI | Gonzalez | Demoted to reserve roster | | | Before |
| 5/13/2010 | PHI | Miller | Released | | | Before |
| 5/13/2010 | PIT | Bernadina | Released | | | Before |
| 5/13/2010 | PIT | Bernadina | Signed | | | Before |
| 5/13/2010 | PIT | Bernadina | Signed | | | Before |
| 5/13/2010 | PIT | Fulchino | Demoted to reserve roster | | | Before |
| 5/13/2010 | PIT | Getz | Released | | | Before |
| 5/13/2010 | PIT | Kozma | Promoted to active roster | | | Before |
| 5/13/2010 | PIT | Nova | Signed | | | Before |
| 5/13/2010 | PIT | Rodriguez | Released | | | Before |
| 5/13/2010 | PIT | Rohlinger | Released | | | Before |
| 5/13/2010 | PIT | Rohlinger | Signed | | | Before |
| 5/13/2010 | STL | Hawksworth | Demoted to reserve roster | | | Before |
| 5/13/2010 | STL | Atkins | Acquired via trade | CHN | | After |
| 5/13/2010 | STL | Headley | Traded away | CHN | | After |
| 5/13/2010 | STL | Olsen | Traded away | CHN | | After |
| 5/13/2010 | STL | Penny | Acquired via trade | CHN | | After |
| 5/15/2010 | SF | Byrdak | Demoted to reserve roster | | | Before |
| 5/16/2010 | ARI | Billingsley | Acquired via trade | HOU | | After |
| 5/16/2010 | ARI | Davis | Traded away | HOU | | After |
| 5/16/2010 | ARI | Hu | Acquired via trade | HOU | | After |
| 5/16/2010 | ARI | Kapler | Acquired via trade | HOU | | After |
| 5/16/2010 | ARI | Tillman | Traded away | HOU | | After |
| 5/16/2010 | CHN | Aardsma | Traded away | SF | | After |
| 5/16/2010 | CHN | Crain | Acquired via trade | SF | | After |
| 5/16/2010 | CHN | Headley | Traded away | SF | | After |
| 5/16/2010 | CHN | Howry | Acquired via trade | SF | | After |
| 5/16/2010 | CHN | Rolen | Acquired via trade | SF | | After |
| 5/16/2010 | CIN | Hardy | Demoted to reserve roster | | | Before |
| 5/16/2010 | CIN | Kennedy | Promoted to active roster | | | Before |
| 5/16/2010 | HOU | Billingsley | Traded away | ARI | | After |
| 5/16/2010 | HOU | Davis | Acquired via trade | ARI | | After |
| 5/16/2010 | HOU | Hu | Traded away | ARI | | After |
| 5/16/2010 | HOU | Kapler | Traded away | ARI | | After |
| 5/16/2010 | HOU | Tillman | Acquired via trade | ARI | | After |
| 5/16/2010 | SF | Aardsma | Acquired via trade | CHN | | After |
| 5/16/2010 | SF | Crain | Traded away | CHN | | After |
| 5/16/2010 | SF | Headley | Acquired via trade | CHN | | After |
| 5/16/2010 | SF | Howry | Traded away | CHN | | After |
| 5/16/2010 | SF | Rolen | Traded away | CHN | | After |
| 5/17/2010 | ARI | Billingsley | Promoted to active roster | | | Before |
| 5/17/2010 | ARI | Latos | Demoted to reserve roster | | | Before |
| 5/17/2010 | ARI | McDonald | Released | | | Before |
| 5/17/2010 | ARI | Takahashi | Demoted to reserve roster | | | Before |
| 5/17/2010 | ATL | Cousins | Promoted to active roster | | | Before |
| 5/17/2010 | ATL | Jeffress | Demoted to reserve roster | | | Before |
| 5/17/2010 | ATL | Marte | Promoted to active roster | | | Before |
| 5/17/2010 | CHN | Crain | Promoted to active roster | | | Before |
| 5/17/2010 | CHN | Hammel | Demoted to reserve roster | | | Before |
| 5/17/2010 | COL | Lillibridge | Demoted to reserve roster | | | Before |
| 5/17/2010 | COL | Rollins | Promoted to active roster | | | Before |
| 5/17/2010 | NYN | Carter | Promoted to active roster | | | Before |
| 5/17/2010 | NYN | Diaz | Demoted to reserve roster | | | Before |
| 5/17/2010 | PHI | Getz | Signed | | | Before |
| 5/17/2010 | PHI | Getz | Promoted to active roster | | | Before |
| 5/17/2010 | PHI | Smith | Released | | | Before |
| 5/17/2010 | PHI | Tracy | Demoted to reserve roster | | | Before |
| 5/17/2010 | PIT | Cruz | Released | | | Before |
| 5/17/2010 | PIT | Fulchino | Promoted to active roster | | | Before |
| 5/17/2010 | PIT | Rodriguez | Signed | | | Before |
| 5/17/2010 | PIT | Veras | Released | | | Before |
| 5/17/2010 | SF | Betancourt | Promoted to active roster | | | Before |
| 5/17/2010 | SF | Hensley | Demoted to reserve roster | | | Before |
| 5/17/2010 | SF | Hensley | Promoted to active roster | | | Before |
| 5/17/2010 | SF | Jones | Promoted to active roster | | | Before |
| 5/17/2010 | SF | Manzella | Demoted to reserve roster | | | Before |
| 5/17/2010 | STL | Bloomquist | Demoted to reserve roster | | | Before |
| 5/17/2010 | STL | Hawpe | Promoted to active roster | | | Before |
| 5/17/2010 | STL | McGehee | Demoted to reserve roster | | | Before |
| 5/17/2010 | STL | Stavinoha | Signed | | | Before |
| 5/17/2010 | STL | Stavinoha | Promoted to active roster | | | Before |
| 5/17/2010 | WAS | Aceves | Demoted to reserve roster | | | Before |
| 5/17/2010 | WAS | Guthrie | Promoted to active roster | | | Before |
| 5/18/2010 | CIN | Marshall | Demoted to reserve roster | | | Before |
| 5/18/2010 | CIN | Westbrook | Promoted to active roster | | | Before |
| 5/18/2010 | SF | Manzella | Released | | | Before |
| 5/20/2010 | ARI | Chavez | Acquired via trade | NYN | | After |
| 5/20/2010 | ARI | DeJesus | Traded away | NYN | | After |
| 5/20/2010 | ARI | Kuo | Acquired via trade | NYN | | After |
| 5/20/2010 | ARI | Takahashi | Traded away | NYN | | After |
| 5/20/2010 | NYN | Chavez | Traded away | ARI | | After |
| 5/20/2010 | NYN | DeJesus | Acquired via trade | ARI | | After |
| 5/20/2010 | NYN | Kuo | Traded away | ARI | | After |
| 5/20/2010 | NYN | Takahashi | Acquired via trade | ARI | | After |
| 5/21/2010 | ARI | Chirinos | Released | | | Before |
| 5/21/2010 | ARI | Latos | Promoted to active roster | | | Before |
| 5/21/2010 | ARI | Liriano | Demoted to reserve roster | | | Before |
| 5/21/2010 | ARI | Perdomo | Signed | | | Before |
| 5/21/2010 | FLA | Hinske | Signed | | | Before |
| 5/21/2010 | FLA | Ruiz | Released | | | Before |
| 5/21/2010 | FLA | Smith | Signed | | | Before |
| 5/21/2010 | MIL | Bonine | Signed | | | Before |
| 5/21/2010 | MIL | Burton | Promoted to active roster | | | Before |
| 5/21/2010 | MIL | Embree | Released | | | Before |
| 5/21/2010 | MIL | White | Demoted to reserve roster | | | Before |
| 5/21/2010 | NYN | Carter | Demoted to reserve roster | | | Before |
| 5/21/2010 | NYN | Takahashi | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Adams | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Adams | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Adams | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Broxton | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Broxton | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Broxton | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Broxton | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Broxton | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Calero | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Calero | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Feliz | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Feliz | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Fulchino | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Fulchino | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Gervacio | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Gervacio | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Greinke | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Greinke | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Haren | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Haren | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Lincecum | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Lincecum | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Papelbon | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Papelbon | Promoted to active roster | | | Before |
| 5/21/2010 | PIT | Papelbon | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Schoeneweis | Demoted to reserve roster | | | Before |
| 5/21/2010 | PIT | Schoeneweis | Promoted to active roster | | | Before |
| 5/21/2010 | SF | Buscher | Signed | | | Before |
| 5/21/2010 | SF | Santana | Demoted to reserve roster | | | Before |
| 5/22/2010 | PIT | Adams | Promoted to active roster | | | Before |
| 5/22/2010 | PIT | Broxton | Demoted to reserve roster | | | Before |
| 5/22/2010 | PIT | Broxton | Promoted to active roster | | | Before |
| 5/22/2010 | PIT | Feliz | Demoted to reserve roster | | | Before |
| 5/22/2010 | PIT | Papelbon | Demoted to reserve roster | | | Before |
| 5/22/2010 | PIT | Papelbon | Promoted to active roster | | | Before |
| 5/23/2010 | PIT | Broxton | Promoted to active roster | | | Before |
| 5/23/2010 | PIT | Feliz | Promoted to active roster | | | Before |
| 5/23/2010 | PIT | Papelbon | Promoted to active roster | | | Before |
| 5/23/2010 | PIT | Aardsma | Acquired via trade | SF | | After |
| 5/23/2010 | PIT | Beckett | Traded away | SF | | After |
| 5/23/2010 | PIT | Bonderman | Traded away | SF | | After |
| 5/23/2010 | PIT | Feliz | Traded away | SF | | After |
| 5/23/2010 | PIT | Santana | Acquired via trade | SF | | After |
| 5/23/2010 | SF | Aardsma | Traded away | PIT | | After |
| 5/23/2010 | SF | Beckett | Acquired via trade | PIT | | After |
| 5/23/2010 | SF | Bonderman | Acquired via trade | PIT | | After |
| 5/23/2010 | SF | Feliz | Acquired via trade | PIT | | After |
| 5/23/2010 | SF | Santana | Traded away | PIT | | After |
| 5/24/2010 | ARI | Kilby | Released | | | Before |
| 5/24/2010 | CIN | Gillaspie | Signed | | | Before |
| 5/24/2010 | CIN | Laird | Signed | | | Before |
| 5/24/2010 | CIN | Laird | Promoted to active roster | | | Before |
| 5/24/2010 | CIN | Soto | Released | | | Before |
| 5/24/2010 | CIN | Towles | Demoted to reserve roster | | | Before |
| 5/24/2010 | COL | Ethier | Demoted to reserve roster | | | Before |
| 5/24/2010 | COL | Jackson | Promoted to active roster | | | Before |
| 5/24/2010 | COL | Lillibridge | Promoted to active roster | | | Before |
| 5/24/2010 | COL | Rollins | Demoted to reserve roster | | | Before |
| 5/24/2010 | HOU | Mathis | Released | | | Before |
| 5/24/2010 | HOU | Strieby | Signed | | | Before |
| 5/24/2010 | PHI | Cunningham | Promoted to active roster | | | Before |
| 5/24/2010 | PHI | Davis | Demoted to reserve roster | | | Before |
| 5/24/2010 | PHI | DeRosa | Demoted to reserve roster | | | Before |
| 5/24/2010 | PHI | Narveson | Demoted to reserve roster | | | Before |
| 5/24/2010 | PHI | Narveson | Promoted to active roster | | | Before |
| 5/24/2010 | PHI | Tracy | Demoted to reserve roster | | | Before |
| 5/24/2010 | PHI | Tracy | Promoted to active roster | | | Before |
| 5/24/2010 | PHI | Vargas | Promoted to active roster | | | Before |
| 5/24/2010 | PIT | Calero | Released | | | Before |
| 5/24/2010 | PIT | Mientkiewicz | Released | | | Before |
| 5/24/2010 | PIT | Nova | Promoted to active roster | | | Before |
| 5/24/2010 | PIT | Santana | Promoted to active roster | | | Before |
| 5/24/2010 | PIT | Veras | Signed | | | Before |
| 5/24/2010 | SD | Fuentes | Promoted to active roster | | | Before |
| 5/24/2010 | SD | Tucker | Demoted to reserve roster | | | Before |
| 5/24/2010 | SF | Beckett | Demoted to reserve roster | | | Before |
| 5/24/2010 | SF | Buscher | Released | | | Before |
| 5/24/2010 | SF | Furcal | Demoted to reserve roster | | | Before |
| 5/24/2010 | SF | Furcal | Promoted to active roster | | | Before |
| 5/24/2010 | SF | Jepsen | Promoted to active roster | | | Before |
| 5/24/2010 | STL | Bloomquist | Promoted to active roster | | | Before |
| 5/24/2010 | STL | Penny | Demoted to reserve roster | | | Before |
| 5/24/2010 | STL | Sanchez | Promoted to active roster | | | Before |
| 5/24/2010 | STL | Sizemore | Demoted to reserve roster | | | Before |
| 5/24/2010 | STL | Stavinoha | Demoted to reserve roster | | | Before |
| 5/24/2010 | STL | Zagurski | Signed | | | Before |
| 5/24/2010 | STL | Zagurski | Promoted to active roster | | | Before |
| 5/25/2010 | HOU | Blanks | Demoted to reserve roster | | | Before |
| 5/25/2010 | HOU | Davies | Promoted to active roster | | | Before |
| 5/25/2010 | HOU | Hochevar | Promoted to active roster | | | Before |
| 5/25/2010 | HOU | Jackson | Promoted to active roster | | | Before |
| 5/25/2010 | HOU | Schafer | Promoted to active roster | | | Before |
| 5/25/2010 | HOU | Snider | Demoted to reserve roster | | | Before |
| 5/25/2010 | HOU | Young | Promoted to active roster | | | Before |
| 5/25/2010 | WAS | Baker | Promoted to active roster | | | Before |
| 5/25/2010 | WAS | Edmonds | Demoted to reserve roster | | | Before |
| 5/25/2010 | WAS | Gathright | Promoted to active roster | | | Before |
| 5/25/2010 | WAS | Hairston | Demoted to reserve roster | | | Before |
| 5/27/2010 | COL | Adams | Acquired via trade | PIT | | After |
| 5/27/2010 | COL | Buck | Acquired via trade | PIT | | After |
| 5/27/2010 | COL | Dye | Traded away | PIT | | After |
| 5/27/2010 | COL | Ethier | Traded away | PIT | | After |
| 5/27/2010 | COL | Ludwick | Acquired via trade | PIT | | After |
| 5/27/2010 | COL | Saltalamacchia | Traded away | PIT | | After |
| 5/27/2010 | COL | Victorino | Traded away | PIT | | After |
| 5/27/2010 | PIT | Adams | Traded away | COL | | After |
| 5/27/2010 | PIT | Buck | Traded away | COL | | After |
| 5/27/2010 | PIT | Dye | Acquired via trade | COL | | After |
| 5/27/2010 | PIT | Ethier | Acquired via trade | COL | | After |
| 5/27/2010 | PIT | Ludwick | Traded away | COL | | After |
| 5/27/2010 | PIT | Saltalamacchia | Acquired via trade | COL | | After |
| 5/27/2010 | PIT | Victorino | Acquired via trade | COL | | After |
| 5/28/2010 | ARI | Brignac | Demoted to reserve roster | | | Before |
| 5/28/2010 | ARI | Latos | Promoted to active roster | | | Before |
| 5/28/2010 | ARI | Perdomo | Demoted to reserve roster | | | Before |
| 5/28/2010 | ARI | Weeks | Promoted to active roster | | | Before |
| 5/28/2010 | CHN | Abreu | Signed | | | Before |
| 5/28/2010 | CHN | Abreu | Promoted to active roster | | | Before |
| 5/28/2010 | CHN | Aubrey | Released | | | Before |
| 5/28/2010 | CHN | Balentien | Released | | | Before |
| 5/28/2010 | CHN | Bautista | Promoted to active roster | | | Before |
| 5/28/2010 | CHN | Capuano | Signed | | | Before |
| 5/28/2010 | CHN | Chico | Released | | | Before |
| 5/28/2010 | CHN | Francoeur | Demoted to reserve roster | | | Before |
| 5/28/2010 | CHN | Hernandez | Released | | | Before |
| 5/28/2010 | CHN | Parr | Released | | | Before |
| 5/28/2010 | CHN | Sosa | Signed | | | Before |
| 5/28/2010 | CHN | Sosa | Promoted to active roster | | | Before |
| 5/28/2010 | CHN | Sweeney | Signed | | | Before |
| 5/28/2010 | CHN | Zavada | Demoted to reserve roster | | | Before |
| 5/28/2010 | CIN | Lecure | Signed | | | Before |
| 5/28/2010 | CIN | Marshall | Promoted to active roster | | | Before |
| 5/28/2010 | CIN | Martinez | Released | | | Before |
| 5/28/2010 | CIN | Westbrook | Demoted to reserve roster | | | Before |
| 5/28/2010 | COL | Miller | Released | | | Before |
| 5/28/2010 | COL | Mitre | Signed | | | Before |
| 5/28/2010 | NYN | Maine | Demoted to reserve roster | | | Before |
| 5/28/2010 | NYN | Manuel | Promoted to active roster | | | Before |
| 5/28/2010 | NYN | Rzepczynski | Promoted to active roster | | | Before |
| 5/28/2010 | NYN | van den Hurk | Demoted to reserve roster | | | Before |
| 5/28/2010 | PHI | Cunningham | Released | | | Before |
| 5/28/2010 | PHI | Diamond | Signed | | | Before |
| 5/28/2010 | PHI | Garcia | Released | | | Before |
| 5/28/2010 | PHI | Tracy | Released | | | Before |
| 5/28/2010 | PIT | Balentien | Released | | | Before |
| 5/28/2010 | PIT | Balentien | Signed | | | Before |
| 5/28/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 5/28/2010 | PIT | Papelbon | Demoted to reserve roster | | | Before |
| 5/28/2010 | PIT | Wilson | Signed | | | Before |
| 5/28/2010 | SF | Ascanio | Released | | | Before |
| 5/28/2010 | SF | Axford | Signed | | | Before |
| 5/28/2010 | STL | Mather | Demoted to reserve roster | | | Before |
| 5/28/2010 | STL | Miner | Released | | | Before |
| 5/28/2010 | STL | Stavinoha | Promoted to active roster | | | Before |
| 5/29/2010 | ATL | Kiker | Demoted to reserve roster | | | Before |
| 5/29/2010 | ATL | Kiker | Promoted to active roster | | | Before |
| 5/30/2010 | MIL | Chavez | Demoted to reserve roster | | | Before |
| 5/30/2010 | PIT | Hoffpauir | Released | | | Before |
| 5/30/2010 | PIT | Hoffpauir | Signed | | | Before |
| 5/31/2010 | ARI | Brignac | Promoted to active roster | | | Before |
| 5/31/2010 | ARI | Hu | Demoted to reserve roster | | | Before |
| 5/31/2010 | CHN | Allen | Demoted to reserve roster | | | Before |
| 5/31/2010 | CHN | Allen | Promoted to active roster | | | Before |
| 5/31/2010 | CHN | Francoeur | Promoted to active roster | | | Before |
| 5/31/2010 | CHN | Morales | Demoted to reserve roster | | | Before |
| 5/31/2010 | CIN | Hardy | Promoted to active roster | | | Before |
| 5/31/2010 | CIN | Kennedy | Demoted to reserve roster | | | Before |
| 5/31/2010 | MIL | Dominguez | Promoted to active roster | | | Before |
| 5/31/2010 | MIL | Pearce | Demoted to reserve roster | | | Before |
| 5/31/2010 | MIL | Withrow | Promoted to active roster | | | Before |
| 5/31/2010 | NYN | Carter | Promoted to active roster | | | Before |
| 5/31/2010 | NYN | Hanigan | Demoted to reserve roster | | | Before |
| 5/31/2010 | PHI | Belisle | Signed | | | Before |
| 5/31/2010 | PHI | Denorfia | Released | | | Before |
| 5/31/2010 | PHI | Denorfia | Signed | | | Before |
| 5/31/2010 | PHI | Garcia | Signed | | | Before |
| 5/31/2010 | PHI | Gonzalez | Released | | | Before |
| 5/31/2010 | PHI | Narveson | Released | | | Before |
| 5/31/2010 | PHI | Torres | Signed | | | Before |
| 5/31/2010 | PIT | Balentien | Signed | | | Before |
| 5/31/2010 | PIT | Gerut | Demoted to reserve roster | | | Before |
| 5/31/2010 | PIT | Hoffpauir | Signed | | | Before |
| 5/31/2010 | PIT | Jacobs | Signed | | | Before |
| 5/31/2010 | PIT | Kozma | Demoted to reserve roster | | | Before |
| 5/31/2010 | PIT | Ottavino | Signed | | | Before |
| 5/31/2010 | PIT | Papelbon | Promoted to active roster | | | Before |
| 5/31/2010 | PIT | Schoeneweis | Released | | | Before |
| 5/31/2010 | PIT | Wilson | Released | | | Before |
| 5/31/2010 | STL | Bloomquist | Demoted to reserve roster | | | Before |
| 5/31/2010 | STL | Downs | Demoted to reserve roster | | | Before |
| 5/31/2010 | STL | Hawksworth | Promoted to active roster | | | Before |
| 5/31/2010 | STL | Izturis | Promoted to active roster | | | Before |
| 5/31/2010 | WAS | Bianchi | Released | | | Before |
| 5/31/2010 | WAS | Hernandez | Signed | | | Before |
| 6/1/2010 | ATL | Bailey | Demoted to reserve roster | | | Before |
| 6/1/2010 | ATL | Cousins | Demoted to reserve roster | | | Before |
| 6/1/2010 | ATL | Kiker | Demoted to reserve roster | | | Before |
| 6/1/2010 | COL | Kieschnick | Promoted to active roster | | | Before |
| 6/1/2010 | COL | Rodriguez | Demoted to reserve roster | | | Before |
| 6/1/2010 | WAS | Cruz | Promoted to active roster | | | Before |
| 6/1/2010 | WAS | Gathright | Demoted to reserve roster | | | Before |
| 6/1/2010 | WAS | Morton | Demoted to reserve roster | | | Before |
| 6/1/2010 | WAS | Ohlendorf | Promoted to active roster | | | Before |
| 6/3/2010 | CHN | Abreu | Traded away | WAS | | After |
| 6/3/2010 | CHN | Fuld | Traded away | WAS | | After |
| 6/3/2010 | CHN | Gardner | Acquired via trade | WAS | | After |
| 6/3/2010 | CHN | Guthrie | Acquired via trade | WAS | | After |
| 6/3/2010 | CHN | Howry | Traded away | WAS | | After |
| 6/3/2010 | CHN | Pennington | Traded away | WAS | | After |
| 6/3/2010 | CHN | Theriot | Acquired via trade | WAS | | After |
| 6/3/2010 | CHN | Walden | Acquired via trade | WAS | | After |
| 6/3/2010 | CHN | Young | Traded away | WAS | | After |
| 6/3/2010 | CHN | Young | Traded away | WAS | | After |
| 6/3/2010 | WAS | Abreu | Acquired via trade | CHN | | After |
| 6/3/2010 | WAS | Fuld | Acquired via trade | CHN | | After |
| 6/3/2010 | WAS | Gardner | Traded away | CHN | | After |
| 6/3/2010 | WAS | Guthrie | Traded away | CHN | | After |
| 6/3/2010 | WAS | Howry | Acquired via trade | CHN | | After |
| 6/3/2010 | WAS | Pennington | Acquired via trade | CHN | | After |
| 6/3/2010 | WAS | Theriot | Traded away | CHN | | After |
| 6/3/2010 | WAS | Walden | Traded away | CHN | | After |
| 6/3/2010 | WAS | Young | Acquired via trade | CHN | | After |
| 6/3/2010 | WAS | Young | Acquired via trade | CHN | | After |
| 6/4/2010 | ATL | Shouse | Signed | | | Before |
| 6/4/2010 | FLA | Bautista | Signed | | | Before |
| 6/4/2010 | FLA | Choate | Released | | | Before |
| 6/4/2010 | FLA | Figaro | Released | | | Before |
| 6/4/2010 | FLA | Lindsey | Released | | | Before |
| 6/4/2010 | FLA | Lindsey | Signed | | | Before |
| 6/4/2010 | PHI | Narveson | Signed | | | Before |
| 6/4/2010 | PIT | Rodriguez | Released | | | Before |
| 6/4/2010 | SD | McCarthy | Demoted to reserve roster | | | Before |
| 6/4/2010 | SD | Robertson | Promoted to active roster | | | Before |
| 6/4/2010 | SD | Thompson | Demoted to reserve roster | | | Before |
| 6/4/2010 | SD | Tucker | Promoted to active roster | | | Before |
| 6/4/2010 | STL | Hawksworth | Demoted to reserve roster | | | Before |
| 6/4/2010 | STL | Mather | Promoted to active roster | | | Before |
| 6/4/2010 | WAS | Baker | Demoted to reserve roster | | | Before |
| 6/4/2010 | WAS | Baker | Promoted to active roster | | | Before |
| 6/4/2010 | WAS | Gray | Demoted to reserve roster | | | Before |
| 6/4/2010 | WAS | Huff | Demoted to reserve roster | | | Before |
| 6/4/2010 | WAS | Ohlendorf | Demoted to reserve roster | | | Before |
| 6/4/2010 | WAS | Ohlendorf | Promoted to active roster | | | Before |
| 6/4/2010 | WAS | Pennington | Demoted to reserve roster | | | Before |
| 6/4/2010 | WAS | Pennington | Promoted to active roster | | | Before |
| 6/4/2010 | WAS | Pucetas | Released | | | Before |
| 6/6/2010 | CHN | Aceves | Acquired via trade | WAS | | After |
| 6/6/2010 | CHN | Ohlendorf | Acquired via trade | WAS | | After |
| 6/6/2010 | CHN | Rodriguez | Traded away | WAS | | After |
| 6/6/2010 | WAS | Aceves | Traded away | CHN | | After |
| 6/6/2010 | WAS | Ohlendorf | Traded away | CHN | | After |
| 6/6/2010 | WAS | Rodriguez | Acquired via trade | CHN | | After |
| 6/7/2010 | ARI | Brignac | Demoted to reserve roster | | | Before |
| 6/7/2010 | ARI | Hu | Promoted to active roster | | | Before |
| 6/7/2010 | ATL | Cousins | Promoted to active roster | | | Before |
| 6/7/2010 | ATL | Neshek | Promoted to active roster | | | Before |
| 6/7/2010 | CHN | Capuano | Released | | | Before |
| 6/7/2010 | CHN | Chico | Signed | | | Before |
| 6/7/2010 | CIN | Blackmon | Promoted to active roster | | | Before |
| 6/7/2010 | CIN | Marshall | Demoted to reserve roster | | | Before |
| 6/7/2010 | CIN | Parra | Demoted to reserve roster | | | Before |
| 6/7/2010 | CIN | Westbrook | Promoted to active roster | | | Before |
| 6/7/2010 | MIL | Chavez | Released | | | Before |
| 6/7/2010 | NYN | Castillo | Demoted to reserve roster | | | Before |
| 6/7/2010 | NYN | van den Hurk | Promoted to active roster | | | Before |
| 6/7/2010 | PHI | Torres | Promoted to active roster | | | Before |
| 6/7/2010 | PIT | Chavez | Signed | | | Before |
| 6/7/2010 | PIT | Ethier | Promoted to active roster | | | Before |
| 6/7/2010 | PIT | Hoffpauir | Demoted to reserve roster | | | Before |
| 6/7/2010 | PIT | Ross | Demoted to reserve roster | | | Before |
| 6/7/2010 | PIT | Shoppach | Promoted to active roster | | | Before |
| 6/7/2010 | WAS | Cruz | Demoted to reserve roster | | | Before |
| 6/7/2010 | WAS | Edmonds | Promoted to active roster | | | Before |
| 6/8/2010 | COL | Kieschnick | Demoted to reserve roster | | | Before |
| 6/8/2010 | FLA | Johnson | Released | | | Before |
| 6/10/2010 | FLA | Johnson | Released | | | Before |
| 6/10/2010 | FLA | Johnson | Signed | | | Before |
| 6/11/2010 | CIN | Bulger | Demoted to reserve roster | | | Before |
| 6/11/2010 | CIN | del Rosario | Promoted to active roster | | | Before |
| 6/11/2010 | CIN | Hardy | Demoted to reserve roster | | | Before |
| 6/11/2010 | CIN | Kennedy | Promoted to active roster | | | Before |
| 6/11/2010 | FLA | Smith | Released | | | Before |
| 6/11/2010 | PHI | Emaus | Released | | | Before |
| 6/11/2010 | PIT | Balentien | Released | | | Before |
| 6/11/2010 | PIT | Hoffpauir | Released | | | Before |
| 6/11/2010 | PIT | Stairs | Signed | | | Before |
| 6/11/2010 | STL | Gwynn | Signed | | | Before |
| 6/11/2010 | STL | Gwynn | Promoted to active roster | | | Before |
| 6/11/2010 | STL | Stavinoha | Demoted to reserve roster | | | Before |
| 6/13/2010 | PHI | McClellan | Traded away | OAK | | After |
| 6/13/2010 | PHI | Qualls | Acquired via trade | OAK | | After |
| 6/14/2010 | ARI | Brignac | Promoted to active roster | | | Before |
| 6/14/2010 | ARI | Kapler | Demoted to reserve roster | | | Before |
| 6/14/2010 | FLA | Duke | Promoted to active roster | | | Before |
| 6/14/2010 | FLA | Ramirez | Demoted to reserve roster | | | Before |
| 6/14/2010 | MIL | Dominguez | Demoted to reserve roster | | | Before |
| 6/14/2010 | MIL | Kratz | Demoted to reserve roster | | | Before |
| 6/14/2010 | MIL | Kratz | Promoted to active roster | | | Before |
| 6/14/2010 | MIL | Montero | Promoted to active roster | | | Before |
| 6/14/2010 | PHI | Belisle | Promoted to active roster | | | Before |
| 6/14/2010 | PHI | Vargas | Demoted to reserve roster | | | Before |
| 6/14/2010 | PIT | Atkins | Signed | | | Before |
| 6/14/2010 | PIT | Jacobs | Released | | | Before |
| 6/14/2010 | PIT | Kozma | Promoted to active roster | | | Before |
| 6/14/2010 | PIT | Ross | Promoted to active roster | | | Before |
| 6/14/2010 | PIT | Stairs | Released | | | Before |
| 6/14/2010 | STL | Hawksworth | Promoted to active roster | | | Before |
| 6/14/2010 | STL | Smith | Demoted to reserve roster | | | Before |
| 6/15/2010 | ATL | Jeffress | Promoted to active roster | | | Before |
| 6/17/2010 | PIT | Beltran | Acquired via trade | WAS | | After |
| 6/17/2010 | PIT | Gutierrez | Traded away | WAS | | After |
| 6/17/2010 | WAS | Beltran | Traded away | PIT | | After |
| 6/17/2010 | WAS | Gutierrez | Acquired via trade | PIT | | After |
| 6/18/2010 | FLA | Bell | Released | | | Before |
| 6/18/2010 | PHI | Cunningham | Signed | | | Before |
| 6/18/2010 | PHI | Narveson | Released | | | Before |
| 6/18/2010 | PIT | Albaladejo | Signed | | | Before |
| 6/18/2010 | PIT | Albaladejo | Promoted to active roster | | | Before |
| 6/18/2010 | PIT | Atkins | Released | | | Before |
| 6/18/2010 | PIT | Gervacio | Demoted to reserve roster | | | Before |
| 6/18/2010 | PIT | Ottavino | Released | | | Before |
| 6/18/2010 | STL | Hawksworth | Demoted to reserve roster | | | Before |
| 6/18/2010 | STL | Smith | Promoted to active roster | | | Before |
| 6/20/2010 | SF | Barton | Acquired via trade | KC | | After |
| 6/20/2010 | SF | Pence | Traded away | KC | | After |
| 6/21/2010 | ARI | Billingsley | Demoted to reserve roster | | | Before |
| 6/21/2010 | ARI | Pelfrey | Promoted to active roster | | | Before |
| 6/21/2010 | FLA | Maxwell | Promoted to active roster | | | Before |
| 6/21/2010 | FLA | Tulowitzki | Demoted to reserve roster | | | Before |
| 6/21/2010 | PIT | Chavez | Released | | | Before |
| 6/21/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 6/21/2010 | SF | Betancourt | Demoted to reserve roster | | | Before |
| 6/21/2010 | SF | Byrdak | Promoted to active roster | | | Before |
| 6/21/2010 | SF | Cowgill | Signed | | | Before |
| 6/21/2010 | SF | Furcal | Promoted to active roster | | | Before |
| 6/21/2010 | SF | Hermida | Demoted to reserve roster | | | Before |
| 6/21/2010 | SF | Lidge | Promoted to active roster | | | Before |
| 6/21/2010 | SF | Ortiz | Released | | | Before |
| 6/21/2010 | STL | Bloomquist | Promoted to active roster | | | Before |
| 6/21/2010 | STL | Izturis | Demoted to reserve roster | | | Before |
| 6/21/2010 | STL | Stavinoha | Demoted to reserve roster | | | Before |
| 6/21/2010 | STL | Stavinoha | Promoted to active roster | | | Before |
| 6/21/2010 | WAS | Venable | Demoted to reserve roster | | | Before |
| 6/22/2010 | COL | Mitre | Demoted to reserve roster | | | Before |
| 6/22/2010 | PHI | Daley | Demoted to reserve roster | | | Before |
| 6/24/2010 | PHI | Blake | Acquired via trade | OAK | | After |
| 6/24/2010 | PHI | Francisco | Acquired via trade | OAK | | After |
| 6/24/2010 | PHI | Ross | Traded away | OAK | | After |
| 6/24/2010 | PHI | Vargas | Traded away | OAK | | After |
| 6/25/2010 | ARI | Liriano | Demoted to reserve roster | | | Before |
| 6/25/2010 | ARI | Liriano | Promoted to active roster | | | Before |
| 6/25/2010 | CHN | Hoffpauir | Signed | | | Before |
| 6/25/2010 | FLA | Dessens | Signed | | | Before |
| 6/25/2010 | FLA | Hairston | Released | | | Before |
| 6/25/2010 | FLA | Manzella | Released | | | Before |
| 6/25/2010 | FLA | Manzella | Signed | | | Before |
| 6/25/2010 | FLA | McGowan | Released | | | Before |
| 6/25/2010 | PHI | Dobbs | Demoted to reserve roster | | | Before |
| 6/25/2010 | PHI | Dobbs | Promoted to active roster | | | Before |
| 6/25/2010 | PHI | Romero | Demoted to reserve roster | | | Before |
| 6/25/2010 | PHI | Romero | Promoted to active roster | | | Before |
| 6/25/2010 | PIT | Bozied | Signed | | | Before |
| 6/25/2010 | SF | Cowgill | Released | | | Before |
| 6/25/2010 | STL | Stavinoha | Promoted to active roster | | | Before |
| 6/25/2010 | STL | Zagurski | Demoted to reserve roster | | | Before |
| 6/28/2010 | FLA | Sanchez | Signed | | | Before |
| 6/28/2010 | PHI | Dobbs | Released | | | Before |
| 6/28/2010 | PHI | Durbin | Demoted to reserve roster | | | Before |
| 6/28/2010 | PHI | Ortiz | Signed | | | Before |
| 6/28/2010 | PHI | Ortiz | Promoted to active roster | | | Before |
| 6/28/2010 | PHI | Romero | Promoted to active roster | | | Before |
| 6/28/2010 | SD | Pedroia | Demoted to reserve roster | | | Before |
| 6/28/2010 | STL | Bloomquist | Demoted to reserve roster | | | Before |
| 6/28/2010 | STL | Hawksworth | Promoted to active roster | | | Before |
| 6/28/2010 | STL | Koplove | Promoted to active roster | | | Before |
| 6/28/2010 | STL | Stavinoha | Demoted to reserve roster | | | Before |
| 6/30/2010 | COL | Rodriguez | Promoted to active roster | | | Before |
| 6/30/2010 | COL | Rollins | Promoted to active roster | | | Before |
| 6/30/2010 | WAS | Lowell | Demoted to reserve roster | | | Before |
| 7/1/2010 | CIN | Breslow | Promoted to active roster | | | Before |
| 7/1/2010 | CIN | DeHoyos | Demoted to reserve roster | | | Before |
| 7/1/2010 | CIN | Fox | Signed | | | Before |
| 7/1/2010 | CIN | Gillaspie | Released | | | Before |
| 7/1/2010 | CIN | Marshall | Promoted to active roster | | | Before |
| 7/1/2010 | CIN | Storey | Signed | | | Before |
| 7/1/2010 | CIN | Konerko | Traded away | COL | | After |
| 7/1/2010 | CIN | Ludwick | Acquired via trade | COL | | After |
| 7/1/2010 | CIN | Ordonez | Traded away | COL | | After |
| 7/1/2010 | COL | MacDougal | Released | | | Before |
| 7/1/2010 | COL | Ryan | Released | | | Before |
| 7/1/2010 | COL | Konerko | Acquired via trade | CIN | | After |
| 7/1/2010 | COL | Ludwick | Traded away | CIN | | After |
| 7/1/2010 | COL | Ordonez | Acquired via trade | CIN | | After |
| 7/1/2010 | MIL | Diaz | Released | | | Before |
| 7/1/2010 | MIL | Enright | Signed | | | Before |
| 7/1/2010 | MIL | Watson | Signed | | | Before |
| 7/1/2010 | MIL | Watson | Promoted to active roster | | | Before |
| 7/1/2010 | PHI | Cunningham | Released | | | Before |
| 7/1/2010 | PHI | Guzman | Released | | | Before |
| 7/1/2010 | PHI | Narveson | Signed | | | Before |
| 7/1/2010 | PHI | Schneider | Signed | | | Before |
| 7/1/2010 | PIT | Albaladejo | Demoted to reserve roster | | | Before |
| 7/1/2010 | PIT | Cordero | Signed | | | Before |
| 7/1/2010 | PIT | Cordero | Promoted to active roster | | | Before |
| 7/1/2010 | PIT | Thurston | Signed | | | Before |
| 7/1/2010 | PIT | Thurston | Demoted to reserve roster | | | Before |
| 7/1/2010 | PIT | Tracy | Signed | | | Before |
| 7/1/2010 | SF | Berken | Released | | | Before |
| 7/1/2010 | SF | Berken | Signed | | | Before |
| 7/1/2010 | SF | Reyes | Signed | | | Before |
| 7/1/2010 | STL | Bloomquist | Promoted to active roster | | | Before |
| 7/1/2010 | STL | Hawksworth | Demoted to reserve roster | | | Before |
| 7/1/2010 | STL | Koplove | Demoted to reserve roster | | | Before |
| 7/1/2010 | STL | Zagurski | Promoted to active roster | | | Before |
| 7/5/2010 | ARI | Belisario | Demoted to reserve roster | | | Before |
| 7/5/2010 | ARI | Billingsley | Promoted to active roster | | | Before |
| 7/5/2010 | ARI | Chavez | Promoted to active roster | | | Before |
| 7/5/2010 | ARI | Hu | Demoted to reserve roster | | | Before |
| 7/5/2010 | ARI | Kapler | Promoted to active roster | | | Before |
| 7/5/2010 | ARI | Pelfrey | Demoted to reserve roster | | | Before |
| 7/5/2010 | ATL | Alonso | Demoted to reserve roster | | | Before |
| 7/5/2010 | CIN | Bailey | Promoted to active roster | | | Before |
| 7/5/2010 | CIN | Hardy | Promoted to active roster | | | Before |
| 7/5/2010 | CIN | Kennedy | Demoted to reserve roster | | | Before |
| 7/5/2010 | CIN | Ludwick | Demoted to reserve roster | | | Before |
| 7/5/2010 | LAD | Donnelly | Promoted to active roster | | | Before |
| 7/5/2010 | LAD | Heyward | Demoted to reserve roster | | | Before |
| 7/5/2010 | LAD | Pavano | Demoted to reserve roster | | | Before |
| 7/5/2010 | LAD | Pavano | Promoted to active roster | | | Before |
| 7/5/2010 | LAD | Pavano | Promoted to active roster | | | Before |
| 7/5/2010 | LAD | Raynor | Promoted to active roster | | | Before |
| 7/5/2010 | LAD | Zumaya | Demoted to reserve roster | | | Before |
| 7/5/2010 | MIL | Norris | Promoted to active roster | | | Before |
| 7/5/2010 | MIL | Withrow | Demoted to reserve roster | | | Before |
| 7/5/2010 | NYN | Diaz | Promoted to active roster | | | Before |
| 7/5/2010 | NYN | Hernandez | Demoted to reserve roster | | | Before |
| 7/5/2010 | NYN | Hernandez | Promoted to active roster | | | Before |
| 7/5/2010 | NYN | Walker | Demoted to reserve roster | | | Before |
| 7/5/2010 | PHI | Martinez | Demoted to reserve roster | | | Before |
| 7/5/2010 | PHI | Schneider | Promoted to active roster | | | Before |
| 7/5/2010 | PIT | Albaladejo | Promoted to active roster | | | Before |
| 7/5/2010 | PIT | Fulchino | Demoted to reserve roster | | | Before |
| 7/5/2010 | PIT | Polanco | Demoted to reserve roster | | | Before |
| 7/5/2010 | PIT | Thurston | Promoted to active roster | | | Before |
| 7/5/2010 | SF | Patterson | Signed | | | Before |
| 7/5/2010 | SF | Reyes | Released | | | Before |
| 7/5/2010 | STL | Bloomquist | Demoted to reserve roster | | | Before |
| 7/5/2010 | STL | Downs | Promoted to active roster | | | Before |
| 7/5/2010 | STL | Jurrjens | Promoted to active roster | | | Before |
| 7/5/2010 | STL | Zagurski | Demoted to reserve roster | | | Before |
| 7/7/2010 | SD | Scott | Demoted to reserve roster | | | Before |
| 7/9/2010 | ARI | Brignac | Demoted to reserve roster | | | Before |
| 7/9/2010 | ARI | Liriano | Promoted to active roster | | | Before |
| 7/9/2010 | CIN | Fox | Released | | | Before |
| 7/9/2010 | CIN | Ishikawa | Signed | | | Before |
| 7/9/2010 | MIL | Blevins | Demoted to reserve roster | | | Before |
| 7/9/2010 | MIL | Brown | Signed | | | Before |
| 7/9/2010 | MIL | Brown | Promoted to active roster | | | Before |
| 7/9/2010 | MIL | Miller | Demoted to reserve roster | | | Before |
| 7/9/2010 | MIL | Morales | Promoted to active roster | | | Before |
| 7/9/2010 | MIL | White | Released | | | Before |
| 7/9/2010 | NYN | Parnell | Signed | | | Before |
| 7/9/2010 | NYN | Santeliz | Released | | | Before |
| 7/9/2010 | PHI | Belisle | Demoted to reserve roster | | | Before |
| 7/9/2010 | PIT | Bozied | Released | | | Before |
| 7/9/2010 | PIT | Fox | Signed | | | Before |
| 7/9/2010 | PIT | Fulchino | Released | | | Before |
| 7/11/2010 | PHI | Byrdak | Acquired via trade | SF | | After |
| 7/11/2010 | PHI | Gorzelanny | Acquired via trade | SF | | After |
| 7/11/2010 | PHI | Harris | Acquired via trade | SF | | After |
| 7/11/2010 | PHI | Motte | Traded away | SF | | After |
| 7/11/2010 | PHI | Nolasco | Acquired via trade | SF | | After |
| 7/11/2010 | PHI | Peavy | Traded away | SF | | After |
| 7/11/2010 | PHI | Roberts | Traded away | SF | | After |
| 7/11/2010 | SF | Byrdak | Traded away | PHI | | After |
| 7/11/2010 | SF | Gorzelanny | Traded away | PHI | | After |
| 7/11/2010 | SF | Harris | Traded away | PHI | | After |
| 7/11/2010 | SF | Motte | Acquired via trade | PHI | | After |
| 7/11/2010 | SF | Nolasco | Traded away | PHI | | After |
| 7/11/2010 | SF | Peavy | Acquired via trade | PHI | | After |
| 7/11/2010 | SF | Roberts | Acquired via trade | PHI | | After |
| 7/15/2010 | ARI | Frieri | Signed | | | Before |
| 7/15/2010 | ATL | Poreda | Signed | | | Before |
| 7/15/2010 | ATL | Shouse | Released | | | Before |
| 7/15/2010 | CIN | Bond | Signed | | | Before |
| 7/15/2010 | CIN | Choo | Demoted to reserve roster | | | Before |
| 7/15/2010 | CIN | Cooper | Signed | | | Before |
| 7/15/2010 | CIN | DeHoyos | Promoted to active roster | | | Before |
| 7/15/2010 | CIN | Heisey | Promoted to active roster | | | Before |
| 7/15/2010 | CIN | Helton | Demoted to reserve roster | | | Before |
| 7/15/2010 | CIN | Kennedy | Promoted to active roster | | | Before |
| 7/15/2010 | CIN | Marshall | Demoted to reserve roster | | | Before |
| 7/15/2010 | CIN | Poreda | Released | | | Before |
| 7/15/2010 | PHI | Madson | Promoted to active roster | | | Before |
| 7/15/2010 | PHI | Maier | Released | | | Before |
| 7/15/2010 | PHI | Mortensen | Signed | | | Before |
| 7/15/2010 | PHI | Narveson | Released | | | Before |
| 7/15/2010 | PHI | Romero | Demoted to reserve roster | | | Before |
| 7/15/2010 | PIT | Beltran | Promoted to active roster | | | Before |
| 7/15/2010 | PIT | Kozma | Demoted to reserve roster | | | Before |
| 7/15/2010 | PIT | Springer | Released | | | Before |
| 7/15/2010 | PIT | Springer | Signed | | | Before |
| 7/15/2010 | WAS | Cruz | Promoted to active roster | | | Before |
| 7/15/2010 | WAS | Edmonds | Demoted to reserve roster | | | Before |
| 7/15/2010 | WAS | Hairston | Promoted to active roster | | | Before |
| 7/16/2010 | PIT | Beltran | Demoted to reserve roster | | | Before |
| 7/16/2010 | PIT | Kozma | Promoted to active roster | | | Before |
| 7/16/2010 | SF | Gallardo | Demoted to reserve roster | | | Before |
| 7/17/2010 | SD | Delcarmen | Demoted to reserve roster | | | Before |
| 7/18/2010 | CIN | Breslow | Demoted to reserve roster | | | Before |
| 7/18/2010 | CIN | Ishikawa | Promoted to active roster | | | Before |
| 7/18/2010 | PIT | Beltran | Demoted to reserve roster | | | Before |
| 7/18/2010 | PIT | Beltran | Promoted to active roster | | | Before |
| 7/18/2010 | PIT | Polanco | Demoted to reserve roster | | | Before |
| 7/18/2010 | PIT | Polanco | Promoted to active roster | | | Before |
| 7/19/2010 | ARI | Latos | Demoted to reserve roster | | | Before |
| 7/19/2010 | ARI | Perdomo | Promoted to active roster | | | Before |
| 7/19/2010 | CIN | Heisey | Demoted to reserve roster | | | Before |
| 7/19/2010 | CIN | Heisey | Promoted to active roster | | | Before |
| 7/19/2010 | CIN | Spilborghs | Demoted to reserve roster | | | Before |
| 7/19/2010 | CIN | Spilborghs | Promoted to active roster | | | Before |
| 7/19/2010 | LAD | Campillo | Demoted to reserve roster | | | Before |
| 7/19/2010 | LAD | Heyward | Promoted to active roster | | | Before |
| 7/19/2010 | LAD | Pavano | Demoted to reserve roster | | | Before |
| 7/19/2010 | LAD | Volquez | Promoted to active roster | | | Before |
| 7/19/2010 | MIL | Harang | Demoted to reserve roster | | | Before |
| 7/19/2010 | MIL | Withrow | Promoted to active roster | | | Before |
| 7/19/2010 | NYN | Hanigan | Promoted to active roster | | | Before |
| 7/19/2010 | NYN | Johnson | Demoted to reserve roster | | | Before |
| 7/19/2010 | PHI | Durbin | Promoted to active roster | | | Before |
| 7/19/2010 | PHI | Miller | Demoted to reserve roster | | | Before |
| 7/19/2010 | PIT | Beltran | Promoted to active roster | | | Before |
| 7/19/2010 | PIT | Cordero | Released | | | Before |
| 7/19/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 7/19/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 7/19/2010 | PIT | Polanco | Promoted to active roster | | | Before |
| 7/19/2010 | PIT | Saltalamacchia | Demoted to reserve roster | | | Before |
| 7/19/2010 | PIT | Springer | Signed | | | Before |
| 7/19/2010 | PIT | Thurston | Released | | | Before |
| 7/19/2010 | SD | Kelly | Promoted to active roster | | | Before |
| 7/19/2010 | SD | Navarro | Promoted to active roster | | | Before |
| 7/19/2010 | SD | Reddick | Promoted to active roster | | | Before |
| 7/19/2010 | SF | Betancourt | Demoted to reserve roster | | | Before |
| 7/19/2010 | SF | Betancourt | Promoted to active roster | | | Before |
| 7/19/2010 | SF | Bonderman | Promoted to active roster | | | Before |
| 7/19/2010 | SF | Patterson | Promoted to active roster | | | Before |
| 7/19/2010 | SF | Peavy | Demoted to reserve roster | | | Before |
| 7/19/2010 | SF | Silva | Promoted to active roster | | | Before |
| 7/19/2010 | SF | Stauffer | Promoted to active roster | | | Before |
| 7/20/2010 | COL | Adams | Demoted to reserve roster | | | Before |
| 7/21/2010 | ATL | Morneau | Demoted to reserve roster | | | Before |
| 7/21/2010 | FLA | Hernandez | Demoted to reserve roster | | | Before |
| 7/22/2010 | CIN | Kotchman | Acquired via trade | SF | | After |
| 7/22/2010 | CIN | Parra | Traded away | SF | | After |
| 7/22/2010 | SF | Beckett | Traded away | DET | | After |
| 7/22/2010 | SF | Kotchman | Traded away | CIN | | After |
| 7/22/2010 | SF | Lidge | Traded away | DET | | After |
| 7/22/2010 | SF | Markakis | Acquired via trade | DET | | After |
| 7/22/2010 | SF | Parra | Acquired via trade | CIN | | After |
| 7/22/2010 | SF | Roberts | Traded away | DET | | After |
| 7/23/2010 | ARI | Pelfrey | Promoted to active roster | | | Before |
| 7/23/2010 | ARI | Perdomo | Demoted to reserve roster | | | Before |
| 7/23/2010 | CIN | Baldelli | Signed | | | Before |
| 7/23/2010 | CIN | Baldelli | Promoted to active roster | | | Before |
| 7/23/2010 | CIN | Heisey | Demoted to reserve roster | | | Before |
| 7/23/2010 | CIN | Ishikawa | Demoted to reserve roster | | | Before |
| 7/23/2010 | CIN | Marshall | Promoted to active roster | | | Before |
| 7/23/2010 | CIN | Towles | Released | | | Before |
| 7/23/2010 | CIN | Westbrook | Demoted to reserve roster | | | Before |
| 7/23/2010 | FLA | de la Rosa | Promoted to active roster | | | Before |
| 7/23/2010 | FLA | Dessens | Demoted to reserve roster | | | Before |
| 7/23/2010 | FLA | Dessens | Promoted to active roster | | | Before |
| 7/23/2010 | FLA | Duke | Demoted to reserve roster | | | Before |
| 7/23/2010 | FLA | Duke | Promoted to active roster | | | Before |
| 7/23/2010 | FLA | Ramirez | Promoted to active roster | | | Before |
| 7/23/2010 | FLA | Sanchez | Promoted to active roster | | | Before |
| 7/23/2010 | FLA | Wheeler | Demoted to reserve roster | | | Before |
| 7/23/2010 | HOU | Jackson | Demoted to reserve roster | | | Before |
| 7/23/2010 | MIL | Bonine | Released | | | Before |
| 7/23/2010 | MIL | Isringhausen | Signed | | | Before |
| 7/23/2010 | PHI | Diamond | Released | | | Before |
| 7/23/2010 | SF | Berken | Signed | | | Before |
| 7/23/2010 | SF | Patterson | Released | | | Before |
| 7/23/2010 | WAS | Atilano | Released | | | Before |
| 7/23/2010 | WAS | Gomez | Signed | | | Before |
| 7/25/2010 | ATL | Hafner | Traded away | PIT | | After |
| 7/25/2010 | ATL | Morneau | Traded away | SEA | | After |
| 7/25/2010 | ATL | Schlereth | Acquired via trade | SEA | | After |
| 7/25/2010 | ATL | Sizemore | Acquired via trade | SEA | | After |
| 7/25/2010 | PIT | Hafner | Acquired via trade | ATL | | After |
| 7/26/2010 | ARI | Liriano | Demoted to reserve roster | | | Before |
| 7/26/2010 | ARI | Liriano | Promoted to active roster | | | Before |
| 7/26/2010 | ATL | Cousins | Released | | | Before |
| 7/26/2010 | CIN | Baldelli | Demoted to reserve roster | | | Before |
| 7/26/2010 | CIN | Choo | Promoted to active roster | | | Before |
| 7/26/2010 | CIN | Ludwick | Promoted to active roster | | | Before |
| 7/26/2010 | CIN | Sweeney | Demoted to reserve roster | | | Before |
| 7/26/2010 | COL | Mitre | Promoted to active roster | | | Before |
| 7/26/2010 | COL | Ordonez | Demoted to reserve roster | | | Before |
| 7/26/2010 | FLA | Castro | Signed | | | Before |
| 7/26/2010 | FLA | Castro | Promoted to active roster | | | Before |
| 7/26/2010 | FLA | Church | Demoted to reserve roster | | | Before |
| 7/26/2010 | FLA | Crawford | Demoted to reserve roster | | | Before |
| 7/26/2010 | FLA | Crawford | Promoted to active roster | | | Before |
| 7/26/2010 | FLA | Dessens | Released | | | Before |
| 7/26/2010 | FLA | Herrera | Signed | | | Before |
| 7/26/2010 | FLA | Herrera | Promoted to active roster | | | Before |
| 7/26/2010 | FLA | Maxwell | Demoted to reserve roster | | | Before |
| 7/26/2010 | FLA | Patterson | Signed | | | Before |
| 7/26/2010 | FLA | Patterson | Promoted to active roster | | | Before |
| 7/26/2010 | FLA | Peguero | Demoted to reserve roster | | | Before |
| 7/26/2010 | FLA | Peguero | Promoted to active roster | | | Before |
| 7/26/2010 | MIL | Isringhausen | Promoted to active roster | | | Before |
| 7/26/2010 | MIL | Withrow | Demoted to reserve roster | | | Before |
| 7/26/2010 | NYN | Castillo | Promoted to active roster | | | Before |
| 7/26/2010 | NYN | DeJesus | Demoted to reserve roster | | | Before |
| 7/26/2010 | PIT | Kozma | Demoted to reserve roster | | | Before |
| 7/26/2010 | STL | Atkins | Demoted to reserve roster | | | Before |
| 7/26/2010 | STL | Downs | Demoted to reserve roster | | | Before |
| 7/26/2010 | STL | Izturis | Promoted to active roster | | | Before |
| 7/26/2010 | STL | McGehee | Promoted to active roster | | | Before |
| 7/27/2010 | LAD | Pettitte | Demoted to reserve roster | | | Before |
| 7/28/2010 | ATL | Kazmir | Demoted to reserve roster | | | Before |
| 7/28/2010 | CIN | Marshall | Demoted to reserve roster | | | Before |
| 7/28/2010 | CIN | Westbrook | Promoted to active roster | | | Before |
| 7/29/2010 | CIN | Hamilton | Traded away | NYA | | After |
| 7/29/2010 | CIN | Jennings | Acquired via trade | NYA | | After |
| 7/29/2010 | CIN | McAllister | Traded away | NYA | | After |
| 7/29/2010 | CIN | Vazquez | Acquired via trade | NYA | | After |
| 7/29/2010 | PHI | Raburn | Acquired via trade | STL | | After |
| 7/29/2010 | STL | Raburn | Traded away | PHI | | After |
| 7/30/2010 | CIN | Bond | Released | | | Before |
| 7/30/2010 | CIN | Westbrook | Demoted to reserve roster | | | Before |
| 7/30/2010 | FLA | Affeldt | Demoted to reserve roster | | | Before |
| 7/30/2010 | FLA | Benoit | Demoted to reserve roster | | | Before |
| 7/30/2010 | FLA | Benoit | Promoted to active roster | | | Before |
| 7/30/2010 | FLA | Figueroa | Released | | | Before |
| 7/30/2010 | FLA | Romero | Signed | | | Before |
| 7/30/2010 | FLA | Romero | Promoted to active roster | | | Before |
| 7/30/2010 | MIL | Coghlan | Demoted to reserve roster | | | Before |
| 7/30/2010 | MIL | Strasburg | Demoted to reserve roster | | | Before |
| 7/30/2010 | MIL | Withrow | Promoted to active roster | | | Before |
| 7/30/2010 | MIL | Wood | Promoted to active roster | | | Before |
| 7/30/2010 | PHI | Romero | Released | | | Before |
| 7/30/2010 | PHI | Torres | Demoted to reserve roster | | | Before |
| 7/30/2010 | PIT | Tejeda | Signed | | | Before |
| 7/30/2010 | PIT | Tracy | Released | | | Before |
| 7/30/2010 | STL | Downs | Promoted to active roster | | | Before |
| 8/1/2010 | CIN | Roberts | Acquired via trade | DET | | After |
| 8/1/2010 | CIN | Wood | Traded away | DET | | After |
| 8/1/2010 | PIT | Bloomquist | Acquired via trade | STL | | After |
| 8/1/2010 | PIT | Hawpe | Acquired via trade | STL | | After |
| 8/1/2010 | PIT | Jakubauskas | Traded away | STL | | After |
| 8/1/2010 | PIT | Mather | Acquired via trade | STL | | After |
| 8/1/2010 | PIT | Molina | Acquired via trade | STL | | After |
| 8/1/2010 | PIT | Victorino | Traded away | STL | | After |
| 8/1/2010 | STL | Bloomquist | Traded away | PIT | | After |
| 8/1/2010 | STL | Hawpe | Traded away | PIT | | After |
| 8/1/2010 | STL | Jakubauskas | Acquired via trade | PIT | | After |
| 8/1/2010 | STL | Mather | Traded away | PIT | | After |
| 8/1/2010 | STL | Molina | Traded away | PIT | | After |
| 8/1/2010 | STL | Victorino | Acquired via trade | PIT | | After |
| 8/2/2010 | ARI | Bailey | Demoted to reserve roster | | | Before |
| 8/2/2010 | ARI | Latos | Promoted to active roster | | | Before |
| 8/2/2010 | ARI | Pelfrey | Demoted to reserve roster | | | Before |
| 8/2/2010 | ARI | Perdomo | Demoted to reserve roster | | | Before |
| 8/2/2010 | ARI | Perdomo | Promoted to active roster | | | Before |
| 8/2/2010 | ARI | Pie | Promoted to active roster | | | Before |
| 8/2/2010 | CHN | Sosa | Released | | | Before |
| 8/2/2010 | CIN | Bailey | Demoted to reserve roster | | | Before |
| 8/2/2010 | CIN | Breslow | Promoted to active roster | | | Before |
| 8/2/2010 | CIN | del Rosario | Demoted to reserve roster | | | Before |
| 8/2/2010 | CIN | Maholm | Demoted to reserve roster | | | Before |
| 8/2/2010 | CIN | Marshall | Promoted to active roster | | | Before |
| 8/2/2010 | PHI | Arias | Demoted to reserve roster | | | Before |
| 8/2/2010 | PHI | Martinez | Promoted to active roster | | | Before |
| 8/2/2010 | PHI | Schneider | Demoted to reserve roster | | | Before |
| 8/2/2010 | PHI | Torres | Promoted to active roster | | | Before |
| 8/2/2010 | PIT | Bernadina | Demoted to reserve roster | | | Before |
| 8/2/2010 | PIT | Bloomquist | Promoted to active roster | | | Before |
| 8/2/2010 | PIT | Ross | Demoted to reserve roster | | | Before |
| 8/2/2010 | PIT | Tejeda | Released | | | Before |
| 8/2/2010 | SF | Axford | Promoted to active roster | | | Before |
| 8/2/2010 | SF | Berken | Promoted to active roster | | | Before |
| 8/2/2010 | SF | Hensley | Promoted to active roster | | | Before |
| 8/2/2010 | SF | Hermida | Promoted to active roster | | | Before |
| 8/2/2010 | SF | O'Flaherty | Demoted to reserve roster | | | Before |
| 8/2/2010 | SF | Parra | Promoted to active roster | | | Before |
| 8/2/2010 | SF | Pinto | Demoted to reserve roster | | | Before |
| 8/2/2010 | SF | Silva | Demoted to reserve roster | | | Before |
| 8/2/2010 | STL | Cervelli | Promoted to active roster | | | Before |
| 8/2/2010 | STL | Overbay | Promoted to active roster | | | Before |
| 8/2/2010 | STL | Petit | Released | | | Before |
| 8/2/2010 | STL | Victorino | Demoted to reserve roster | | | Before |
| 8/2/2010 | STL | Zagurski | Promoted to active roster | | | Before |
| 8/5/2010 | ARI | Anderson | Released | | | Before |
| 8/5/2010 | ARI | Chavez | Demoted to reserve roster | | | Before |
| 8/5/2010 | ARI | Hester | Signed | | | Before |
| 8/5/2010 | ARI | Kapler | Demoted to reserve roster | | | Before |
| 8/5/2010 | ARI | Kapler | Promoted to active roster | | | Before |
| 8/5/2010 | ARI | Liriano | Demoted to reserve roster | | | Before |
| 8/5/2010 | ARI | McDonald | Signed | | | Before |
| 8/5/2010 | ARI | McDonald | Promoted to active roster | | | Before |
| 8/5/2010 | ARI | Anderson | Acquired via trade | KC | | After |
| 8/5/2010 | ARI | Fister | Traded away | KC | | After |
| 8/5/2010 | ARI | Frasor | Acquired via trade | KC | | After |
| 8/5/2010 | ARI | Perdomo | Traded away | KC | | After |
| 8/5/2010 | CIN | Bailey | Promoted to active roster | | | Before |
| 8/5/2010 | CIN | Breslow | Demoted to reserve roster | | | Before |
| 8/5/2010 | CIN | del Rosario | Promoted to active roster | | | Before |
| 8/5/2010 | CIN | Kennedy | Demoted to reserve roster | | | Before |
| 8/5/2010 | CIN | Maholm | Promoted to active roster | | | Before |
| 8/5/2010 | CIN | Marshall | Demoted to reserve roster | | | Before |
| 8/5/2010 | PHI | Diamond | Signed | | | Before |
| 8/5/2010 | PHI | Maier | Signed | | | Before |
| 8/5/2010 | PHI | Schneider | Released | | | Before |
| 8/5/2010 | WAS | Wigginton | Acquired via trade | KC | | After |
| 8/6/2010 | SD | Eckstein | Demoted to reserve roster | | | Before |
| 8/9/2010 | ARI | Hester | Promoted to active roster | | | Before |
| 8/9/2010 | ARI | Santana | Demoted to reserve roster | | | Before |
| 8/9/2010 | CIN | Cook | Demoted to reserve roster | | | Before |
| 8/9/2010 | CIN | Helton | Promoted to active roster | | | Before |
| 8/9/2010 | CIN | Kotchman | Demoted to reserve roster | | | Before |
| 8/9/2010 | CIN | Westbrook | Promoted to active roster | | | Before |
| 8/9/2010 | PIT | Bernadina | Promoted to active roster | | | Before |
| 8/9/2010 | PIT | Hafner | Demoted to reserve roster | | | Before |
| 8/9/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 8/9/2010 | PIT | Springer | Demoted to reserve roster | | | Before |
| 8/9/2010 | SF | Martin | Demoted to reserve roster | | | Before |
| 8/9/2010 | SF | Simon | Promoted to active roster | | | Before |
| 8/9/2010 | STL | Stavinoha | Promoted to active roster | | | Before |
| 8/10/2010 | CHN | Gutierrez | Demoted to reserve roster | | | Before |
| 8/10/2010 | WAS | Prado | Demoted to reserve roster | | | Before |
| 8/12/2010 | SF | Arrieta | Acquired via trade | CHA | | After |
| 8/12/2010 | SF | Barton | Traded away | CHA | | After |
| 8/12/2010 | SF | Headley | Traded away | CHA | | After |
| 8/12/2010 | SF | Peavy | Traded away | CHA | | After |
| 8/12/2010 | SF | Rios | Traded away | CHA | | After |
| 8/12/2010 | SF | Smoak | Acquired via trade | CHA | | After |
| 8/12/2010 | SF | Zimmerman | Acquired via trade | CHA | | After |
| 8/13/2010 | CIN | Breslow | Promoted to active roster | | | Before |
| 8/13/2010 | CIN | Westbrook | Demoted to reserve roster | | | Before |
| 8/13/2010 | FLA | Church | Promoted to active roster | | | Before |
| 8/13/2010 | FLA | Hernandez | Demoted to reserve roster | | | Before |
| 8/13/2010 | FLA | Hernandez | Promoted to active roster | | | Before |
| 8/13/2010 | FLA | Patterson | Demoted to reserve roster | | | Before |
| 8/13/2010 | FLA | Soto | Demoted to reserve roster | | | Before |
| 8/13/2010 | FLA | Soto | Promoted to active roster | | | Before |
| 8/13/2010 | HOU | Medlen | Demoted to reserve roster | | | Before |
| 8/13/2010 | PHI | Garcia | Released | | | Before |
| 8/13/2010 | PHI | Gibbons | Signed | | | Before |
| 8/13/2010 | PHI | Maier | Released | | | Before |
| 8/13/2010 | PHI | Narveson | Signed | | | Before |
| 8/13/2010 | SF | Arrieta | Promoted to active roster | | | Before |
| 8/13/2010 | SF | Betancourt | Promoted to active roster | | | Before |
| 8/13/2010 | SF | Furcal | Demoted to reserve roster | | | Before |
| 8/13/2010 | SF | Motte | Demoted to reserve roster | | | Before |
| 8/13/2010 | SF | Robinson | Promoted to active roster | | | Before |
| 8/13/2010 | SF | Smoak | Promoted to active roster | | | Before |
| 8/15/2010 | WAS | Gomez | Traded away | CLE | | After |
| 8/15/2010 | WAS | Padilla | Acquired via trade | CLE | | After |
| 8/15/2010 | WAS | Venable | Traded away | CLE | | After |
| 8/16/2010 | ARI | Belisario | Promoted to active roster | | | Before |
| 8/16/2010 | ARI | Kapler | Demoted to reserve roster | | | Before |
| 8/16/2010 | ARI | Logan | Signed | | | Before |
| 8/16/2010 | CIN | Jones | Demoted to reserve roster | | | Before |
| 8/16/2010 | CIN | Kotchman | Promoted to active roster | | | Before |
| 8/16/2010 | FLA | Soto | Demoted to reserve roster | | | Before |
| 8/16/2010 | MIL | Cueto | Demoted to reserve roster | | | Before |
| 8/16/2010 | MIL | Strasburg | Promoted to active roster | | | Before |
| 8/16/2010 | PHI | Gibbons | Released | | | Before |
| 8/16/2010 | PIT | Bernadina | Demoted to reserve roster | | | Before |
| 8/16/2010 | PIT | Gerut | Promoted to active roster | | | Before |
| 8/16/2010 | STL | Stavinoha | Demoted to reserve roster | | | Before |
| 8/16/2010 | STL | Victorino | Promoted to active roster | | | Before |
| 8/19/2010 | NYN | Johnson | Acquired via trade | SEA | | After |
| 8/19/2010 | NYN | Lowe | Traded away | SEA | | After |
| 8/19/2010 | NYN | Scarpetta | Acquired via trade | SEA | | After |
| 8/19/2010 | NYN | Shields | Traded away | SEA | | After |
| 8/19/2010 | NYN | Villanueva | Traded away | SEA | | After |
| 8/20/2010 | NYN | Figueroa | Signed | | | Before |
| 8/20/2010 | NYN | Walker | Released | | | Before |
| 8/20/2010 | PHI | Bullington | Signed | | | Before |
| 8/20/2010 | PHI | Diamond | Released | | | Before |
| 8/20/2010 | SD | Okajima | Demoted to reserve roster | | | Before |
| 8/22/2010 | ARI | Capps | Traded away | KC | | After |
| 8/22/2010 | ARI | Damon | Acquired via trade | KC | | After |
| 8/23/2010 | ARI | Kapler | Released | | | Before |
| 8/23/2010 | ARI | Liriano | Promoted to active roster | | | Before |
| 8/23/2010 | ARI | Pie | Demoted to reserve roster | | | Before |
| 8/23/2010 | CHN | Donald | Promoted to active roster | | | Before |
| 8/23/2010 | CHN | Erbe | Promoted to active roster | | | Before |
| 8/23/2010 | CHN | Hammel | Promoted to active roster | | | Before |
| 8/23/2010 | CHN | Hoffpauir | Promoted to active roster | | | Before |
| 8/23/2010 | CHN | Olsen | Promoted to active roster | | | Before |
| 8/23/2010 | CHN | Paulino | Demoted to reserve roster | | | Before |
| 8/23/2010 | CHN | Sweeney | Promoted to active roster | | | Before |
| 8/23/2010 | CHN | Willingham | Demoted to reserve roster | | | Before |
| 8/23/2010 | MIL | Hawkins | Signed | | | Before |
| 8/23/2010 | MIL | Isringhausen | Released | | | Before |
| 8/23/2010 | NYN | Acosta | Signed | | | Before |
| 8/23/2010 | PHI | Arias | Promoted to active roster | | | Before |
| 8/23/2010 | PHI | Gload | Demoted to reserve roster | | | Before |
| 8/23/2010 | PIT | Hafner | Promoted to active roster | | | Before |
| 8/23/2010 | PIT | Mather | Demoted to reserve roster | | | Before |
| 8/23/2010 | SF | Berken | Released | | | Before |
| 8/23/2010 | SF | Pinto | Released | | | Before |
| 8/23/2010 | SF | Rhymes | Signed | | | Before |
| 8/23/2010 | STL | Boggs | Promoted to active roster | | | Before |
| 8/23/2010 | STL | Gwynn | Released | | | Before |
| 8/23/2010 | WAS | Cruz | Demoted to reserve roster | | | Before |
| 8/23/2010 | WAS | Feldman | Demoted to reserve roster | | | Before |
| 8/23/2010 | WAS | Morton | Promoted to active roster | | | Before |
| 8/23/2010 | WAS | Padilla | Demoted to reserve roster | | | Before |
| 8/25/2010 | COL | Glaus | Demoted to reserve roster | | | Before |
| 8/25/2010 | SD | K-Rod | Demoted to reserve roster | | | Before |
| 8/27/2010 | CHN | Coleman | Signed | | | Before |
| 8/27/2010 | CHN | Miranda | Promoted to active roster | | | Before |
| 8/27/2010 | CHN | Sweeney | Released | | | Before |
| 8/27/2010 | FLA | Affeldt | Promoted to active roster | | | Before |
| 8/27/2010 | FLA | Hernandez | Promoted to active roster | | | Before |
| 8/27/2010 | FLA | Wheeler | Demoted to reserve roster | | | Before |
| 8/27/2010 | LAD | Campillo | Released | | | Before |
| 8/27/2010 | LAD | Donnelly | Released | | | Before |
| 8/27/2010 | LAD | Johnson | Released | | | Before |
| 8/27/2010 | STL | Atkins | Released | | | Before |
| 8/27/2010 | STL | Boggs | Demoted to reserve roster | | | Before |
| 8/27/2010 | STL | Jakubauskas | Promoted to active roster | | | Before |
| 8/27/2010 | STL | Stavinoha | Promoted to active roster | | | Before |
| 8/27/2010 | STL | Zagurski | Demoted to reserve roster | | | Before |
| 8/28/2010 | PIT | Bernadina | Promoted to active roster | | | Before |
| 8/28/2010 | PIT | Gerut | Demoted to reserve roster | | | Before |
| 8/30/2010 | ARI | Bailey | Promoted to active roster | | | Before |
| 8/30/2010 | ARI | Liriano | Demoted to reserve roster | | | Before |
| 8/30/2010 | CHN | Coleman | Promoted to active roster | | | Before |
| 8/30/2010 | CHN | Ohlendorf | Demoted to reserve roster | | | Before |
| 8/30/2010 | CIN | Corpas | Demoted to reserve roster | | | Before |
| 8/30/2010 | CIN | Westbrook | Promoted to active roster | | | Before |
| 8/30/2010 | FLA | Castro | Demoted to reserve roster | | | Before |
| 8/30/2010 | FLA | Soto | Promoted to active roster | | | Before |
| 8/30/2010 | MIL | Cueto | Promoted to active roster | | | Before |
| 8/30/2010 | MIL | Gamel | Promoted to active roster | | | Before |
| 8/30/2010 | MIL | Strasburg | Demoted to reserve roster | | | Before |
| 8/30/2010 | PHI | Bullington | Released | | | Before |
| 8/30/2010 | PHI | Hernandez | Signed | | | Before |
| 8/30/2010 | PHI | Nunez | Signed | | | Before |
| 8/30/2010 | PIT | Fulchino | Signed | | | Before |
| 8/30/2010 | PIT | Fulchino | Promoted to active roster | | | Before |
| 8/30/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 8/30/2010 | STL | Boggs | Promoted to active roster | | | Before |
| 8/30/2010 | STL | Espinosa | Promoted to active roster | | | Before |
| 8/30/2010 | STL | Francisco | Demoted to reserve roster | | | Before |
| 8/30/2010 | STL | Izturis | Demoted to reserve roster | | | Before |
| 8/30/2010 | STL | Jakubauskas | Demoted to reserve roster | | | Before |
| 8/30/2010 | STL | Koplove | Promoted to active roster | | | Before |
| 9/2/2010 | ARI | Glaus | Acquired via trade | COL | | After |
| 9/2/2010 | ARI | Hester | Traded away | COL | | After |
| 9/2/2010 | ARI | Lowell | Acquired via trade | WAS | | After |
| 9/2/2010 | ARI | Rodriguez | Acquired via trade | COL | | After |
| 9/2/2010 | CHN | Bautista | Traded away | LAD | | After |
| 9/2/2010 | CHN | Coke | Traded away | MIL | | After |
| 9/2/2010 | CHN | Forsythe | Acquired via trade | LAD | | After |
| 9/2/2010 | CHN | Gardner | Traded away | WAS | | After |
| 9/2/2010 | CHN | Guthrie | Traded away | WAS | | After |
| 9/2/2010 | CHN | Hoffpauir | Traded away | HOU | | After |
| 9/2/2010 | CHN | McCutchen | Traded away | HOU | | After |
| 9/2/2010 | CHN | McDonald | Acquired via trade | HOU | | After |
| 9/2/2010 | CHN | Montero | Acquired via trade | MIL | | After |
| 9/2/2010 | CHN | Morales | Traded away | MIL | | After |
| 9/2/2010 | CHN | Mortensen | Acquired via trade | PHI | | After |
| 9/2/2010 | CHN | Prado | Acquired via trade | WAS | | After |
| 9/2/2010 | CHN | Rolen | Traded away | LAD | | After |
| 9/2/2010 | CHN | Sanchez | Acquired via trade | LAD | | After |
| 9/2/2010 | CHN | Tabata | Acquired via trade | LAD | | After |
| 9/2/2010 | CHN | Teahen | Acquired via trade | MIN | | After |
| 9/2/2010 | CHN | Tillman | Acquired via trade | HOU | | After |
| 9/2/2010 | CHN | Wells | Traded away | MIN | | After |
| 9/2/2010 | CHN | Willingham | Traded away | PHI | | After |
| 9/2/2010 | CIN | Bartlett | Acquired via trade | KC | | After |
| 9/2/2010 | CIN | Bray | Acquired via trade | HOU | | After |
| 9/2/2010 | CIN | Breslow | Traded away | HOU | | After |
| 9/2/2010 | CIN | Buchholz | Acquired via trade | WAS | | After |
| 9/2/2010 | CIN | Downs | Acquired via trade | STL | | After |
| 9/2/2010 | CIN | Hardy | Traded away | KC | | After |
| 9/2/2010 | CIN | Jennings | Traded away | COL | | After |
| 9/2/2010 | CIN | Lackey | Acquired via trade | COL | | After |
| 9/2/2010 | CIN | Lewis | Traded away | STL | | After |
| 9/2/2010 | CIN | Marshall | Traded away | STL | | After |
| 9/2/2010 | CIN | Troncoso | Acquired via trade | COL | | After |
| 9/2/2010 | CIN | Victorino | Acquired via trade | STL | | After |
| 9/2/2010 | CIN | Westbrook | Traded away | WAS | | After |
| 9/2/2010 | CIN | Wigginton | Acquired via trade | WAS | | After |
| 9/2/2010 | COL | Glaus | Traded away | ARI | | After |
| 9/2/2010 | COL | Hester | Acquired via trade | ARI | | After |
| 9/2/2010 | COL | Jennings | Acquired via trade | CIN | | After |
| 9/2/2010 | COL | Lackey | Traded away | CIN | | After |
| 9/2/2010 | COL | Rodriguez | Traded away | ARI | | After |
| 9/2/2010 | COL | Troncoso | Traded away | CIN | | After |
| 9/2/2010 | FLA | Hoffman | Traded away | PIT | | After |
| 9/2/2010 | FLA | Romero | Traded away | PIT | | After |
| 9/2/2010 | FLA | Veras | Acquired via trade | PIT | | After |
| 9/2/2010 | HOU | Bray | Traded away | CIN | | After |
| 9/2/2010 | HOU | Breslow | Acquired via trade | CIN | | After |
| 9/2/2010 | HOU | Castro | Acquired via trade | KC | | After |
| 9/2/2010 | HOU | Hochevar | Traded away | KC | | After |
| 9/2/2010 | HOU | Hoffpauir | Acquired via trade | CHN | | After |
| 9/2/2010 | HOU | Kalish | Traded away | KC | | After |
| 9/2/2010 | HOU | McCutchen | Acquired via trade | CHN | | After |
| 9/2/2010 | HOU | McDonald | Traded away | CHN | | After |
| 9/2/2010 | HOU | Tillman | Traded away | CHN | | After |
| 9/2/2010 | LAD | Bautista | Acquired via trade | CHN | | After |
| 9/2/2010 | LAD | Forsythe | Traded away | CHN | | After |
| 9/2/2010 | LAD | Rolen | Acquired via trade | CHN | | After |
| 9/2/2010 | LAD | Sanchez | Traded away | CHN | | After |
| 9/2/2010 | LAD | Tabata | Traded away | CHN | | After |
| 9/2/2010 | MIL | Coke | Acquired via trade | CHN | | After |
| 9/2/2010 | MIL | Cunningham | Acquired via trade | DET | | After |
| 9/2/2010 | MIL | Montero | Traded away | CHN | | After |
| 9/2/2010 | MIL | Morales | Acquired via trade | CHN | | After |
| 9/2/2010 | MIL | Watson | Traded away | DET | | After |
| 9/2/2010 | NYN | Putz | Demoted to reserve roster | | | Before |
| 9/2/2010 | PHI | Miller | Traded away | PIT | | After |
| 9/2/2010 | PHI | Mortensen | Traded away | CHN | | After |
| 9/2/2010 | PHI | Willingham | Acquired via trade | CHN | | After |
| 9/2/2010 | PIT | Guerrero | Acquired via trade | CLE | | After |
| 9/2/2010 | PIT | Hoffman | Acquired via trade | FLA | | After |
| 9/2/2010 | PIT | Koplove | Acquired via trade | STL | | After |
| 9/2/2010 | PIT | Miller | Acquired via trade | PHI | | After |
| 9/2/2010 | PIT | Nova | Traded away | CLE | | After |
| 9/2/2010 | PIT | Romero | Acquired via trade | FLA | | After |
| 9/2/2010 | PIT | Saltalamacchia | Traded away | SF | | After |
| 9/2/2010 | PIT | Springer | Traded away | STL | | After |
| 9/2/2010 | PIT | Veras | Traded away | FLA | | After |
| 9/2/2010 | SF | Saltalamacchia | Acquired via trade | PIT | | After |
| 9/2/2010 | STL | Downs | Traded away | CIN | | After |
| 9/2/2010 | STL | Jakubauskas | Traded away | MIN | | After |
| 9/2/2010 | STL | Koplove | Traded away | PIT | | After |
| 9/2/2010 | STL | Lewis | Acquired via trade | CIN | | After |
| 9/2/2010 | STL | Marshall | Acquired via trade | CIN | | After |
| 9/2/2010 | STL | Springer | Acquired via trade | PIT | | After |
| 9/2/2010 | STL | Victorino | Traded away | CIN | | After |
| 9/2/2010 | WAS | Buchholz | Traded away | CIN | | After |
| 9/2/2010 | WAS | Gardner | Acquired via trade | CHN | | After |
| 9/2/2010 | WAS | Guthrie | Acquired via trade | CHN | | After |
| 9/2/2010 | WAS | Lowell | Traded away | ARI | | After |
| 9/2/2010 | WAS | Prado | Traded away | CHN | | After |
| 9/2/2010 | WAS | Westbrook | Acquired via trade | CIN | | After |
| 9/2/2010 | WAS | Wigginton | Traded away | CIN | | After |
| 9/3/2010 | ARI | Brignac | Promoted to active roster | | | Before |
| 9/3/2010 | ARI | Chavez | Released | | | Before |
| 9/3/2010 | ARI | Glaus | Demoted to reserve roster | | | Before |
| 9/3/2010 | ARI | Glaus | Promoted to active roster | | | Before |
| 9/3/2010 | ARI | Liriano | Promoted to active roster | | | Before |
| 9/3/2010 | ARI | Lowell | Promoted to active roster | | | Before |
| 9/3/2010 | ARI | Pelfrey | Promoted to active roster | | | Before |
| 9/3/2010 | ARI | Pie | Promoted to active roster | | | Before |
| 9/3/2010 | CHN | Blanco | Signed | | | Before |
| 9/3/2010 | CHN | Coleman | Released | | | Before |
| 9/3/2010 | CIN | Atkins | Released | | | Before |
| 9/3/2010 | CIN | Atkins | Signed | | | Before |
| 9/3/2010 | CIN | Baldelli | Promoted to active roster | | | Before |
| 9/3/2010 | CIN | Bray | Promoted to active roster | | | Before |
| 9/3/2010 | CIN | Ishikawa | Released | | | Before |
| 9/3/2010 | CIN | Kennedy | Promoted to active roster | | | Before |
| 9/3/2010 | CIN | Lecure | Released | | | Before |
| 9/3/2010 | CIN | McKenry | Promoted to active roster | | | Before |
| 9/3/2010 | FLA | Bautista | Released | | | Before |
| 9/3/2010 | FLA | Bell | Signed | | | Before |
| 9/3/2010 | FLA | Church | Released | | | Before |
| 9/3/2010 | FLA | Herrera | Released | | | Before |
| 9/3/2010 | HOU | Abreu | Released | | | Before |
| 9/3/2010 | HOU | Thompson | Signed | | | Before |
| 9/3/2010 | MIL | Brown | Released | | | Before |
| 9/3/2010 | MIL | Cunningham | Promoted to active roster | | | Before |
| 9/3/2010 | MIL | Dominguez | Promoted to active roster | | | Before |
| 9/3/2010 | MIL | Harang | Promoted to active roster | | | Before |
| 9/3/2010 | MIL | Lopez | Signed | | | Before |
| 9/3/2010 | MIL | Lopez | Promoted to active roster | | | Before |
| 9/3/2010 | MIL | Scales | Released | | | Before |
| 9/3/2010 | PHI | Arias | Demoted to reserve roster | | | Before |
| 9/3/2010 | PHI | Diamond | Signed | | | Before |
| 9/3/2010 | PHI | Nunez | Promoted to active roster | | | Before |
| 9/3/2010 | PIT | Gerut | Promoted to active roster | | | Before |
| 9/3/2010 | PIT | Kozma | Promoted to active roster | | | Before |
| 9/3/2010 | PIT | Mather | Promoted to active roster | | | Before |
| 9/3/2010 | PIT | Miller | Promoted to active roster | | | Before |
| 9/3/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 9/3/2010 | PIT | Ross | Promoted to active roster | | | Before |
| 9/3/2010 | SF | Kendall | Released | | | Before |
| 9/3/2010 | SF | Martinez | Signed | | | Before |
| 9/3/2010 | SF | May | Signed | | | Before |
| 9/3/2010 | SF | Simon | Released | | | Before |
| 9/3/2010 | STL | Hawksworth | Promoted to active roster | | | Before |
| 9/3/2010 | STL | Marshall | Promoted to active roster | | | Before |
| 9/5/2010 | FLA | Benoit | Demoted to reserve roster | | | Before |
| 9/5/2010 | FLA | Benoit | Promoted to active roster | | | Before |
| 9/5/2010 | FLA | Dessens | Promoted to active roster | | | Before |
| 9/5/2010 | FLA | Duke | Demoted to reserve roster | | | Before |
| 9/5/2010 | FLA | Wheeler | Demoted to reserve roster | | | Before |
| 9/5/2010 | FLA | Wheeler | Promoted to active roster | | | Before |
| 9/6/2010 | ARI | Glaus | Promoted to active roster | | | Before |
| 9/6/2010 | ARI | Hu | Promoted to active roster | | | Before |
| 9/6/2010 | ARI | Runzler | Promoted to active roster | | | Before |
| 9/6/2010 | ARI | Stewart | Demoted to reserve roster | | | Before |
| 9/6/2010 | CHN | Blanco | Promoted to active roster | | | Before |
| 9/6/2010 | CHN | Carpenter | Promoted to active roster | | | Before |
| 9/6/2010 | CHN | Chico | Promoted to active roster | | | Before |
| 9/6/2010 | CHN | Clement | Demoted to reserve roster | | | Before |
| 9/6/2010 | CHN | Hundley | Promoted to active roster | | | Before |
| 9/6/2010 | CHN | Mortensen | Promoted to active roster | | | Before |
| 9/6/2010 | CHN | Prado | Promoted to active roster | | | Before |
| 9/6/2010 | CHN | Tillman | Promoted to active roster | | | Before |
| 9/6/2010 | CIN | Balentien | Signed | | | Before |
| 9/6/2010 | CIN | Buchholz | Promoted to active roster | | | Before |
| 9/6/2010 | CIN | Bulger | Promoted to active roster | | | Before |
| 9/6/2010 | CIN | Cook | Promoted to active roster | | | Before |
| 9/6/2010 | LAD | Fox | Signed | | | Before |
| 9/6/2010 | PHI | Abreu | Signed | | | Before |
| 9/6/2010 | PHI | Abreu | Promoted to active roster | | | Before |
| 9/6/2010 | PHI | Arias | Released | | | Before |
| 9/6/2010 | PHI | Gload | Promoted to active roster | | | Before |
| 9/6/2010 | PHI | Nolasco | Demoted to reserve roster | | | Before |
| 9/6/2010 | PIT | Fulchino | Released | | | Before |
| 9/6/2010 | SF | Axford | Demoted to reserve roster | | | Before |
| 9/6/2010 | SF | Axford | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Furcal | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Gallardo | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Martinez | Promoted to active roster | | | Before |
| 9/6/2010 | SF | May | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Motte | Promoted to active roster | | | Before |
| 9/6/2010 | SF | O'Flaherty | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Rhymes | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Rizzo | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Robinson | Demoted to reserve roster | | | Before |
| 9/6/2010 | SF | Robinson | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Saltalamacchia | Promoted to active roster | | | Before |
| 9/6/2010 | SF | Silva | Promoted to active roster | | | Before |
| 9/10/2010 | FLA | Adams | Signed | | | Before |
| 9/10/2010 | FLA | Hinske | Released | | | Before |
| 9/10/2010 | FLA | Sanchez | Released | | | Before |
| 9/10/2010 | MIL | Kelly | Released | | | Before |
| 9/10/2010 | MIL | Wells | Signed | | | Before |
| 9/10/2010 | SF | Betancourt | Released | | | Before |
| 9/10/2010 | SF | Turner | Signed | | | Before |
| 9/13/2010 | CIN | Cook | Demoted to reserve roster | | | Before |
| 9/13/2010 | NYN | Acosta | Promoted to active roster | | | Before |
| 9/13/2010 | NYN | Barker | Released | | | Before |
| 9/13/2010 | NYN | Figueroa | Promoted to active roster | | | Before |
| 9/13/2010 | NYN | Hernandez | Promoted to active roster | | | Before |
| 9/13/2010 | NYN | Johnson | Promoted to active roster | | | Before |
| 9/13/2010 | NYN | Lindsey | Signed | | | Before |
| 9/13/2010 | NYN | Lindsey | Promoted to active roster | | | Before |
| 9/13/2010 | NYN | Mejia | Promoted to active roster | | | Before |
| 9/13/2010 | NYN | Putz | Promoted to active roster | | | Before |
| 9/13/2010 | PHI | Daley | Promoted to active roster | | | Before |
| 9/13/2010 | PHI | Diamond | Released | | | Before |
| 9/13/2010 | PHI | Gorzelanny | Demoted to reserve roster | | | Before |
| 9/13/2010 | PHI | Harris | Released | | | Before |
| 9/13/2010 | PIT | Santana | Demoted to reserve roster | | | Before |
| 9/13/2010 | WAS | Betancourt | Signed | | | Before |
| 9/13/2010 | WAS | Gathright | Released | | | Before |
| 9/17/2010 | COL | Adams | Promoted to active roster | | | Before |
| 9/17/2010 | COL | Dunn | Promoted to active roster | | | Before |
| 9/17/2010 | COL | Marquis | Promoted to active roster | | | Before |
| 9/17/2010 | COL | Rollins | Demoted to reserve roster | | | Before |
| 9/17/2010 | COL | Rowell | Promoted to active roster | | | Before |
| 9/17/2010 | FLA | Herrera | Signed | | | Before |
| 9/17/2010 | LAD | Rapada | Signed | | | Before |
| 9/17/2010 | LAD | Rapada | Promoted to active roster | | | Before |
| 9/17/2010 | PHI | Harris | Signed | | | Before |
| 9/17/2010 | PHI | Harris | Promoted to active roster | | | Before |
| 9/17/2010 | PHI | Hernandez | Released | | | Before |
| 9/17/2010 | PHI | Hernandez | Signed | | | Before |
| 9/17/2010 | PHI | McDonald | Signed | | | Before |
| 9/17/2010 | PHI | Torres | Demoted to reserve roster | | | Before |
| 9/17/2010 | PIT | Santana | Demoted to reserve roster | | | Before |
| 9/20/2010 | FLA | Herrera | Released | | | Before |
| 9/20/2010 | FLA | Soto | Demoted to reserve roster | | | Before |
| 9/20/2010 | LAD | Fox | Released | | | Before |
| 9/20/2010 | LAD | Gibbons | Signed | | | Before |
| 9/20/2010 | LAD | Gibbons | Promoted to active roster | | | Before |
| 9/20/2010 | LAD | Pettitte | Promoted to active roster | | | Before |
| 9/20/2010 | SF | Johnson | Demoted to reserve roster | | | Before |
| 9/20/2010 | SF | Silva | Demoted to reserve roster | | | Before |
| 9/20/2010 | SF | Turner | Promoted to active roster | | | Before |
| 9/21/2010 | PHI | Getz | Demoted to reserve roster | | | Before |
| 9/24/2010 | CHN | Coleman | Signed | | | Before |
| 9/24/2010 | CIN | Corpas | Released | | | Before |
| 9/24/2010 | CIN | Duke | Signed | | | Before |
| 9/24/2010 | FLA | Affeldt | Released | | | Before |
| 9/24/2010 | FLA | Duke | Released | | | Before |
| 9/24/2010 | PIT | Santana | Demoted to reserve roster | | | Before |
| 9/24/2010 | SF | Affeldt | Signed | | | Before |
| 9/24/2010 | SF | Turner | Released | | | Before |
| 9/27/2010 | ARI | Bailey | Demoted to reserve roster | | | Before |
| 9/27/2010 | ARI | Stewart | Promoted to active roster | | | Before |
| 9/27/2010 | CIN | Duke | Promoted to active roster | | | Before |
| 9/27/2010 | CIN | Vazquez | Demoted to reserve roster | | | Before |
| 9/27/2010 | PHI | Davis | Released | | | Before |
| 9/27/2010 | PHI | Hernandez | Released | | | Before |
| 9/27/2010 | PHI | Hill | Signed | | | Before |
| 9/27/2010 | SF | May | Released | | | Before |
| 9/27/2010 | STL | Springer | Released | | | Before |
| 9/27/2010 | WAS | Hernandez | Signed | | | Before |
| 9/29/2010 | SF | Saltalamacchia | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Belisle | Promoted to active roster | | | Before |
| 10/1/2010 | PHI | Blanton | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Byrdak | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Correia | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Daley | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Durbin | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Harris | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Harris | Promoted to active roster | | | Before |
| 10/1/2010 | PHI | Harris | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Hill | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Hill | Promoted to active roster | | | Before |
| 10/1/2010 | PHI | Hudson | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Madson | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Masset | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Narveson | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Narveson | Promoted to active roster | | | Before |
| 10/1/2010 | PHI | Ortiz | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Qualls | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Roenicke | Demoted to reserve roster | | | Before |
| 10/1/2010 | PHI | Torres | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Aardsma | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Aardsma | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Aardsma | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Albaladejo | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Albaladejo | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Broxton | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Broxton | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Broxton | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Greinke | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Haren | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Haren | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Haren | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Hoffman | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Hoffman | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Hoffman | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Koplove | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Koplove | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Koplove | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Lincecum | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Lincecum | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Lincecum | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Miller | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Miller | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Miller | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Molina | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Papelbon | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Romero | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Romero | Promoted to active roster | | | Before |
| 10/1/2010 | PIT | Romero | Demoted to reserve roster | | | Before |
| 10/1/2010 | PIT | Shoppach | Demoted to reserve roster | | | Before |
| 10/1/2010 | SF | Giambi | Released | | | Before |
| 10/1/2010 | WAS | Eveland | Released | | | Before |
| 10/1/2010 | WAS | Gray | Released | | | Before |
| 10/1/2010 | WAS | Ojeda | Released | | | Before |
| 10/1/2010 | WAS | Timmons | Released | | | Before |
| 10/2/2010 | PHI | Belisle | Demoted to reserve roster | | | Before |
| 10/2/2010 | PHI | Narveson | Promoted to active roster | | | Before |
| 10/2/2010 | PIT | Albaladejo | Demoted to reserve roster | | | Before |
| 10/2/2010 | PIT | Greinke | Promoted to active roster | | | Before |
| 10/3/2010 | PHI | Hill | Promoted to active roster | | | Before |
| 10/3/2010 | PHI | Narveson | Demoted to reserve roster | | | Before |
| 10/3/2010 | PIT | Greinke | Demoted to reserve roster | | | Before |
| 10/3/2010 | PIT | Monasterios | Promoted to active roster | | | Before |
| 10/5/2010 | ARI | Brignac | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Hessman | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Liriano | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Lowell | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | McDonald | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Pelfrey | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Runzler | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Upton | Demoted to reserve roster | | | Before |
| 10/5/2010 | ARI | Upton | Promoted to active roster | | | Before |
| 10/5/2010 | CIN | Bailey | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | Baldelli | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | Bray | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | DeHoyos | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | del Rosario | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | Duke | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | Kennedy | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | McKenry | Demoted to reserve roster | | | Before |
| 10/5/2010 | CIN | Vazquez | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Abreu | Demoted to reserve roster | | | Before |
| 10/5/2010 | PHI | Belisle | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Blanton | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Byrdak | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Correia | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Daley | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Durbin | Demoted to reserve roster | | | Before |
| 10/5/2010 | PHI | Durbin | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Durbin | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Gorzelanny | Demoted to reserve roster | | | Before |
| 10/5/2010 | PHI | Gorzelanny | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Gorzelanny | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Hill | Demoted to reserve roster | | | Before |
| 10/5/2010 | PHI | Hudson | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Madson | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Masset | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Ortiz | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Qualls | Promoted to active roster | | | Before |
| 10/5/2010 | PHI | Roenicke | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Aardsma | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Broxton | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Gerut | Demoted to reserve roster | | | Before |
| 10/5/2010 | PIT | Greinke | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Haren | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Hoffman | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Koplove | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Kozma | Demoted to reserve roster | | | Before |
| 10/5/2010 | PIT | Lincecum | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Mather | Demoted to reserve roster | | | Before |
| 10/5/2010 | PIT | Miller | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Molina | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Monasterios | Demoted to reserve roster | | | Before |
| 10/5/2010 | PIT | Papelbon | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Romero | Promoted to active roster | | | Before |
| 10/5/2010 | PIT | Ross | Demoted to reserve roster | | | Before |
| 10/5/2010 | PIT | Shoppach | Promoted to active roster | | | Before |
