| Transactions |
| Date | Team | Player | Type | OthTm | EffDate | When |
| 4/4/2009 | KC | Hanrahan | Acquired via trade | MIL | | After |
| 4/4/2009 | KC | Schumaker | Traded away | MIL | | After |
| 4/4/2009 | TOR | Pierzynski | Acquired via trade | MIL | | After |
| 4/7/2009 | KC | Aardsma | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Brown | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | DeLome | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Exposito | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Grudzielanek | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Hinshaw | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Ishikawa | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Negrych | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Rivera | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Shelton | Demoted to reserve roster | | | Before |
| 4/7/2009 | KC | Zink | Demoted to reserve roster | | | Before |
| 4/9/2009 | CLE | Aybar | Traded away | HOU | | After |
| 4/9/2009 | CLE | Byrd | Acquired via trade | HOU | | After |
| 4/9/2009 | CLE | Costanzo | Traded away | HOU | | After |
| 4/9/2009 | CLE | Lincoln | Acquired via trade | HOU | | After |
| 4/9/2009 | CLE | Swarzak | Acquired via trade | HOU | | After |
| 4/9/2009 | TEX | Cox | Traded away | CHN | | After |
| 4/9/2009 | TEX | Lee | Acquired via trade | CHN | | After |
| 4/9/2009 | TEX | Loney | Traded away | CHN | | After |
| 4/9/2009 | TEX | Rodriguez | Traded away | CHN | | After |
| 4/9/2009 | TEX | Wade | Acquired via trade | CHN | | After |
| 4/9/2009 | TEX | Zambrano | Acquired via trade | CHN | | After |
| 4/10/2009 | ANA | Crede | Released | | | Before |
| 4/10/2009 | BOS | Ascanio | Signed | | | Before |
| 4/10/2009 | BOS | Quintero | Released | | | Before |
| 4/10/2009 | CHA | Burton | Demoted to reserve roster | | | Before |
| 4/10/2009 | CHA | Camp | Demoted to reserve roster | | | Before |
| 4/10/2009 | CHA | Camp | Promoted to active roster | | | Before |
| 4/10/2009 | CHA | Lindstrom | Promoted to active roster | | | Before |
| 4/10/2009 | CHA | Lyon | Demoted to reserve roster | | | Before |
| 4/10/2009 | CHA | Lyon | Promoted to active roster | | | Before |
| 4/10/2009 | CHA | Mathes | Demoted to reserve roster | | | Before |
| 4/10/2009 | CHA | Sandoval | Released | | | Before |
| 4/10/2009 | CHA | Suppan | Signed | | | Before |
| 4/10/2009 | OAK | Tankersley | Released | | | Before |
| 4/10/2009 | OAK | Wagner | Signed | | | Before |
| 4/10/2009 | TB | Bell | Promoted to active roster | | | Before |
| 4/10/2009 | TB | Matsui | Demoted to reserve roster | | | Before |
| 4/10/2009 | TB | Strieby | Signed | | | Before |
| 4/10/2009 | TB | Venable | Released | | | Before |
| 4/12/2009 | ANA | Hernandez | Traded away | PIT | | After |
| 4/12/2009 | ANA | Hughes | Acquired via trade | PIT | | After |
| 4/12/2009 | ANA | LaPorta | Traded away | PIT | | After |
| 4/12/2009 | MIN | Gregg | Traded away | WAS | | After |
| 4/12/2009 | MIN | Hicks | Acquired via trade | WAS | | After |
| 4/12/2009 | TB | Acosta | Acquired via trade | PIT | | After |
| 4/12/2009 | TB | Matsui | Traded away | PIT | | After |
| 4/12/2009 | TEX | Anderson | Traded away | MIL | | After |
| 4/12/2009 | TEX | Baldelli | Acquired via trade | MIL | | After |
| 4/13/2009 | ANA | Ortega | Signed | | | Before |
| 4/13/2009 | KC | Venable | Signed | | | Before |
| 4/13/2009 | MIN | Bates | Promoted to active roster | | | Before |
| 4/13/2009 | MIN | Guillen | Demoted to reserve roster | | | Before |
| 4/13/2009 | MIN | Hull | Promoted to active roster | | | Before |
| 4/13/2009 | MIN | Kulbacki | Demoted to reserve roster | | | Before |
| 4/13/2009 | MIN | Lewis | Demoted to reserve roster | | | Before |
| 4/13/2009 | MIN | McPherson | Promoted to active roster | | | Before |
| 4/13/2009 | MIN | Perkins | Promoted to active roster | | | Before |
| 4/13/2009 | NYA | Heyward | Demoted to reserve roster | | | Before |
| 4/13/2009 | OAK | Garrison | Demoted to reserve roster | | | Before |
| 4/13/2009 | OAK | Wagner | Promoted to active roster | | | Before |
| 4/13/2009 | SEA | Thomas | Signed | | | Before |
| 4/13/2009 | TB | Acosta | Demoted to reserve roster | | | Before |
| 4/13/2009 | TOR | Gross | Demoted to reserve roster | | | Before |
| 4/13/2009 | TOR | Murton | Promoted to active roster | | | Before |
| 4/13/2009 | TOR | Ruiz | Demoted to reserve roster | | | Before |
| 4/13/2009 | TOR | Zaun | Promoted to active roster | | | Before |
| 4/15/2009 | CHA | Camp | Promoted to active roster | | | Before |
| 4/15/2009 | CHA | Lindstrom | Demoted to reserve roster | | | Before |
| 4/15/2009 | CHA | Lyon | Demoted to reserve roster | | | Before |
| 4/15/2009 | CHA | Mathes | Promoted to active roster | | | Before |
| 4/16/2009 | NYA | Baker | Acquired via trade | PIT | | After |
| 4/16/2009 | NYA | Heyward | Traded away | PIT | | After |
| 4/16/2009 | NYA | Ramirez | Acquired via trade | PIT | | After |
| 4/17/2009 | BAL | Anderson | Signed | | | Before |
| 4/17/2009 | BAL | Anderson | Promoted to active roster | | | Before |
| 4/17/2009 | BAL | Marte | Released | | | Before |
| 4/17/2009 | BAL | Redmond | Released | | | Before |
| 4/17/2009 | BOS | Carroll | Signed | | | Before |
| 4/17/2009 | BOS | Scales | Signed | | | Before |
| 4/17/2009 | CHA | Link | Released | | | Before |
| 4/17/2009 | CHA | Stults | Signed | | | Before |
| 4/17/2009 | DET | Mijares | Signed | | | Before |
| 4/17/2009 | DET | Rogers | Released | | | Before |
| 4/17/2009 | NYA | Borbon | Demoted to reserve roster | | | Before |
| 4/17/2009 | OAK | Badenhop | Signed | | | Before |
| 4/17/2009 | OAK | Badenhop | Promoted to active roster | | | Before |
| 4/17/2009 | OAK | Garrison | Released | | | Before |
| 4/17/2009 | OAK | Griffey | Demoted to reserve roster | | | Before |
| 4/17/2009 | TEX | Gabbard | Promoted to active roster | | | Before |
| 4/17/2009 | TEX | Watson | Demoted to reserve roster | | | Before |
| 4/19/2009 | ANA | Feliz | Traded away | KC | | After |
| 4/19/2009 | KC | Feliz | Acquired via trade | ANA | | After |
| 4/19/2009 | NYA | Gardner | Acquired via trade | MIL | | After |
| 4/19/2009 | NYA | Heilman | Traded away | MIL | | After |
| 4/20/2009 | ANA | Colvin | Demoted to reserve roster | | | Before |
| 4/20/2009 | ANA | Colvin | Promoted to active roster | | | Before |
| 4/20/2009 | ANA | Colvin | Promoted to active roster | | | Before |
| 4/20/2009 | ANA | Cousins | Released | | | Before |
| 4/20/2009 | ANA | Marte | Signed | | | Before |
| 4/20/2009 | ANA | Marte | Promoted to active roster | | | Before |
| 4/20/2009 | ANA | Morrison | Demoted to reserve roster | | | Before |
| 4/20/2009 | ANA | Ortega | Promoted to active roster | | | Before |
| 4/20/2009 | ANA | Paulino | Promoted to active roster | | | Before |
| 4/20/2009 | ANA | Rivera | Promoted to active roster | | | Before |
| 4/20/2009 | ANA | Santiago | Demoted to reserve roster | | | Before |
| 4/20/2009 | ANA | Schroder | Demoted to reserve roster | | | Before |
| 4/20/2009 | ANA | Sowers | Demoted to reserve roster | | | Before |
| 4/20/2009 | BAL | Still | Released | | | Before |
| 4/20/2009 | BOS | Lowrie | Demoted to reserve roster | | | Before |
| 4/20/2009 | BOS | Navarro | Promoted to active roster | | | Before |
| 4/20/2009 | BOS | Tucker | Promoted to active roster | | | Before |
| 4/20/2009 | BOS | Webb | Demoted to reserve roster | | | Before |
| 4/20/2009 | DET | Gordon | Demoted to reserve roster | | | Before |
| 4/20/2009 | MIN | Brocail | Demoted to reserve roster | | | Before |
| 4/20/2009 | MIN | Patterson | Promoted to active roster | | | Before |
| 4/20/2009 | NYA | Harris | Demoted to reserve roster | | | Before |
| 4/20/2009 | NYA | Herges | Released | | | Before |
| 4/20/2009 | NYA | Herges | Signed | | | Before |
| 4/20/2009 | NYA | Rodriguez | Promoted to active roster | | | Before |
| 4/20/2009 | SEA | Hamulack | Released | | | Before |
| 4/20/2009 | SEA | Percival | Promoted to active roster | | | Before |
| 4/20/2009 | SEA | Rowland-Smith | Demoted to reserve roster | | | Before |
| 4/20/2009 | TB | Acosta | Released | | | Before |
| 4/20/2009 | TB | Below | Released | | | Before |
| 4/20/2009 | TB | Below | Signed | | | Before |
| 4/20/2009 | TEX | Cassel | Demoted to reserve roster | | | Before |
| 4/20/2009 | TEX | Gonzalez | Promoted to active roster | | | Before |
| 4/20/2009 | TEX | Hansack | Demoted to reserve roster | | | Before |
| 4/20/2009 | TEX | Hansack | Promoted to active roster | | | Before |
| 4/20/2009 | TEX | Lamb | Promoted to active roster | | | Before |
| 4/20/2009 | TEX | Mora | Demoted to reserve roster | | | Before |
| 4/20/2009 | TEX | Morse | Signed | | | Before |
| 4/20/2009 | TEX | Wade | Demoted to reserve roster | | | Before |
| 4/20/2009 | TEX | Watson | Released | | | Before |
| 4/20/2009 | TEX | Young | Promoted to active roster | | | Before |
| 4/22/2009 | KC | Aardsma | Promoted to active roster | | | Before |
| 4/22/2009 | KC | Feliz | Demoted to reserve roster | | | Before |
| 4/22/2009 | KC | Litsch | Demoted to reserve roster | | | Before |
| 4/23/2009 | ANA | Marrero | Acquired via trade | PIT | | After |
| 4/23/2009 | ANA | Sowers | Traded away | PIT | | After |
| 4/24/2009 | ANA | Colvin | Promoted to active roster | | | Before |
| 4/24/2009 | ANA | Marrero | Promoted to active roster | | | Before |
| 4/24/2009 | ANA | Marte | Promoted to active roster | | | Before |
| 4/24/2009 | ANA | Morrison | Demoted to reserve roster | | | Before |
| 4/24/2009 | ANA | Ortega | Promoted to active roster | | | Before |
| 4/24/2009 | ANA | Schroder | Demoted to reserve roster | | | Before |
| 4/24/2009 | BOS | Ascanio | Promoted to active roster | | | Before |
| 4/24/2009 | BOS | Carroll | Demoted to reserve roster | | | Before |
| 4/24/2009 | BOS | Carroll | Promoted to active roster | | | Before |
| 4/24/2009 | BOS | Navarro | Demoted to reserve roster | | | Before |
| 4/24/2009 | BOS | Scales | Promoted to active roster | | | Before |
| 4/24/2009 | BOS | Tucker | Demoted to reserve roster | | | Before |
| 4/24/2009 | KC | Aardsma | Demoted to reserve roster | | | Before |
| 4/24/2009 | KC | Feliz | Promoted to active roster | | | Before |
| 4/24/2009 | NYA | Alou | Released | | | Before |
| 4/24/2009 | NYA | Farnsworth | Demoted to reserve roster | | | Before |
| 4/24/2009 | NYA | Herges | Signed | | | Before |
| 4/24/2009 | NYA | Herges | Promoted to active roster | | | Before |
| 4/24/2009 | NYA | Phillips | Signed | | | Before |
| 4/24/2009 | NYA | Phillips | Promoted to active roster | | | Before |
| 4/24/2009 | NYA | Rodriguez | Demoted to reserve roster | | | Before |
| 4/24/2009 | NYA | Rodriguez | Promoted to active roster | | | Before |
| 4/24/2009 | NYA | Sheffield | Demoted to reserve roster | | | Before |
| 4/24/2009 | TEX | Blanco | Signed | | | Before |
| 4/24/2009 | TEX | Jones | Released | | | Before |
| 4/27/2009 | ANA | Gonzalez | Released | | | Before |
| 4/27/2009 | BOS | Buckner | Promoted to active roster | | | Before |
| 4/27/2009 | BOS | Hansen | Demoted to reserve roster | | | Before |
| 4/27/2009 | DET | Lofgren | Signed | | | Before |
| 4/27/2009 | DET | Pina | Signed | | | Before |
| 4/27/2009 | DET | Pina | Promoted to active roster | | | Before |
| 4/27/2009 | MIN | Brocail | Promoted to active roster | | | Before |
| 4/27/2009 | MIN | Byrd | Signed | | | Before |
| 4/27/2009 | MIN | Guillen | Promoted to active roster | | | Before |
| 4/27/2009 | MIN | Hull | Demoted to reserve roster | | | Before |
| 4/27/2009 | MIN | James | Released | | | Before |
| 4/27/2009 | MIN | Lewis | Promoted to active roster | | | Before |
| 4/27/2009 | MIN | Patterson | Demoted to reserve roster | | | Before |
| 4/27/2009 | MIN | Ramos | Demoted to reserve roster | | | Before |
| 4/27/2009 | NYA | Beimel | Demoted to reserve roster | | | Before |
| 4/27/2009 | NYA | Bruney | Demoted to reserve roster | | | Before |
| 4/27/2009 | NYA | Farnsworth | Promoted to active roster | | | Before |
| 4/27/2009 | NYA | Melancon | Promoted to active roster | | | Before |
| 4/27/2009 | NYA | Ryan | Demoted to reserve roster | | | Before |
| 4/27/2009 | NYA | Sheffield | Promoted to active roster | | | Before |
| 4/27/2009 | OAK | Doumit | Demoted to reserve roster | | | Before |
| 4/27/2009 | OAK | Ross | Promoted to active roster | | | Before |
| 4/27/2009 | SEA | Moss | Promoted to active roster | | | Before |
| 4/27/2009 | SEA | Thames | Demoted to reserve roster | | | Before |
| 4/27/2009 | TB | Below | Signed | | | Before |
| 4/27/2009 | TB | Below | Demoted to reserve roster | | | Before |
| 4/27/2009 | TB | Below | Promoted to active roster | | | Before |
| 4/27/2009 | TB | Miller | Demoted to reserve roster | | | Before |
| 4/27/2009 | TB | Tejeda | Signed | | | Before |
| 4/27/2009 | TB | Tejeda | Promoted to active roster | | | Before |
| 4/27/2009 | TEX | Baldelli | Demoted to reserve roster | | | Before |
| 4/27/2009 | TEX | Blanco | Promoted to active roster | | | Before |
| 4/27/2009 | TEX | Borowski | Released | | | Before |
| 4/27/2009 | TEX | Cassel | Promoted to active roster | | | Before |
| 4/30/2009 | KC | Brocail | Acquired via trade | MIN | | After |
| 4/30/2009 | KC | Carpenter | Acquired via trade | PIT | | After |
| 4/30/2009 | KC | Ishikawa | Traded away | PIT | | After |
| 4/30/2009 | KC | Looper | Acquired via trade | PIT | | After |
| 4/30/2009 | KC | Spilborghs | Acquired via trade | PIT | | After |
| 4/30/2009 | KC | Taylor | Traded away | PIT | | After |
| 4/30/2009 | KC | Volquez | Traded away | PIT | | After |
| 4/30/2009 | KC | Wigginton | Acquired via trade | MIN | | After |
| 4/30/2009 | MIN | Brocail | Traded away | KC | | After |
| 4/30/2009 | MIN | Wigginton | Traded away | KC | | After |
| 5/1/2009 | BAL | Hernandez | Released | | | Before |
| 5/1/2009 | BAL | Morales | Signed | | | Before |
| 5/1/2009 | CHA | Burton | Promoted to active roster | | | Before |
| 5/1/2009 | CHA | Coffey | Demoted to reserve roster | | | Before |
| 5/1/2009 | DET | Garcia | Demoted to reserve roster | | | Before |
| 5/1/2009 | DET | Martis | Promoted to active roster | | | Before |
| 5/1/2009 | KC | Feliz | Demoted to reserve roster | | | Before |
| 5/1/2009 | KC | Wigginton | Demoted to reserve roster | | | Before |
| 5/3/2009 | TEX | Baldelli | Traded away | PIT | | After |
| 5/3/2009 | TEX | Matsui | Acquired via trade | PIT | | After |
| 5/3/2009 | TEX | McLouth | Acquired via trade | PIT | | After |
| 5/3/2009 | TEX | Uggla | Traded away | PIT | | After |
| 5/4/2009 | BAL | Kennedy | Demoted to reserve roster | | | Before |
| 5/4/2009 | BAL | Laffey | Promoted to active roster | | | Before |
| 5/4/2009 | CLE | Ambriz | Promoted to active roster | | | Before |
| 5/4/2009 | CLE | Purcey | Demoted to reserve roster | | | Before |
| 5/4/2009 | DET | Howry | Released | | | Before |
| 5/4/2009 | MIN | Hull | Promoted to active roster | | | Before |
| 5/4/2009 | MIN | Lewis | Demoted to reserve roster | | | Before |
| 5/4/2009 | MIN | Patterson | Promoted to active roster | | | Before |
| 5/4/2009 | MIN | Valencia | Promoted to active roster | | | Before |
| 5/4/2009 | NYA | Baker | Demoted to reserve roster | | | Before |
| 5/4/2009 | NYA | Harris | Promoted to active roster | | | Before |
| 5/4/2009 | NYA | Mauer | Promoted to active roster | | | Before |
| 5/4/2009 | NYA | Phillips | Released | | | Before |
| 5/4/2009 | OAK | Ellis | Demoted to reserve roster | | | Before |
| 5/4/2009 | OAK | Garciaparra | Demoted to reserve roster | | | Before |
| 5/4/2009 | OAK | Griffey | Promoted to active roster | | | Before |
| 5/4/2009 | OAK | Keppinger | Promoted to active roster | | | Before |
| 5/4/2009 | TB | Below | Released | | | Before |
| 5/4/2009 | TEX | Blanco | Demoted to reserve roster | | | Before |
| 5/4/2009 | TEX | Lamb | Demoted to reserve roster | | | Before |
| 5/4/2009 | TEX | Mora | Promoted to active roster | | | Before |
| 5/4/2009 | TEX | Schoeneweis | Demoted to reserve roster | | | Before |
| 5/4/2009 | TEX | Wade | Promoted to active roster | | | Before |
| 5/4/2009 | TOR | Ruiz | Promoted to active roster | | | Before |
| 5/4/2009 | TOR | Zaun | Demoted to reserve roster | | | Before |
| 5/6/2009 | KC | Wigginton | Promoted to active roster | | | Before |
| 5/6/2009 | KC | Wolfe | Demoted to reserve roster | | | Before |
| 5/7/2009 | KC | Buchholz | Demoted to reserve roster | | | Before |
| 5/7/2009 | KC | Wolfe | Promoted to active roster | | | Before |
| 5/8/2009 | SEA | Jones | Signed | | | Before |
| 5/8/2009 | TB | Diaz | Signed | | | Before |
| 5/8/2009 | TB | Strieby | Released | | | Before |
| 5/8/2009 | TEX | Gardner | Demoted to reserve roster | | | Before |
| 5/8/2009 | TEX | Hernandez | Signed | | | Before |
| 5/8/2009 | TEX | Schoeneweis | Promoted to active roster | | | Before |
| 5/10/2009 | KC | Aardsma | Promoted to active roster | | | Before |
| 5/10/2009 | KC | Brocail | Demoted to reserve roster | | | Before |
| 5/10/2009 | TB | Bulger | Traded away | WAS | | After |
| 5/10/2009 | TB | Savery | Acquired via trade | FLA | | After |
| 5/10/2009 | TB | Simmons | Acquired via trade | WAS | | After |
| 5/10/2009 | TB | Wheeler | Traded away | FLA | | After |
| 5/11/2009 | ANA | Paulino | Promoted to active roster | | | Before |
| 5/11/2009 | BOS | Ascanio | Released | | | Before |
| 5/11/2009 | DET | Ascanio | Signed | | | Before |
| 5/11/2009 | KC | Aardsma | Demoted to reserve roster | | | Before |
| 5/11/2009 | KC | Hinshaw | Promoted to active roster | | | Before |
| 5/11/2009 | KC | Zink | Released | | | Before |
| 5/11/2009 | SEA | Ankiel | Demoted to reserve roster | | | Before |
| 5/11/2009 | SEA | Hampton | Promoted to active roster | | | Before |
| 5/11/2009 | SEA | Sanchez | Demoted to reserve roster | | | Before |
| 5/11/2009 | TB | Diaz | Promoted to active roster | | | Before |
| 5/11/2009 | TB | Jeroloman | Signed | | | Before |
| 5/11/2009 | TB | Savery | Promoted to active roster | | | Before |
| 5/11/2009 | TB | Simmons | Promoted to active roster | | | Before |
| 5/11/2009 | TB | Tejeda | Released | | | Before |
| 5/11/2009 | TEX | Hansack | Promoted to active roster | | | Before |
| 5/11/2009 | TEX | Zambrano | Demoted to reserve roster | | | Before |
| 5/11/2009 | TOR | Gross | Promoted to active roster | | | Before |
| 5/11/2009 | TOR | Guillen | Demoted to reserve roster | | | Before |
| 5/12/2009 | NYA | Beimel | Promoted to active roster | | | Before |
| 5/12/2009 | NYA | Melancon | Demoted to reserve roster | | | Before |
| 5/12/2009 | NYA | Ramirez | Demoted to reserve roster | | | Before |
| 5/12/2009 | NYA | Rodriguez | Promoted to active roster | | | Before |
| 5/14/2009 | OAK | Griffey | Traded away | PIT | | After |
| 5/15/2009 | DET | Thompson | Released | | | Before |
| 5/15/2009 | OAK | Hinske | Demoted to reserve roster | | | Before |
| 5/15/2009 | OAK | Hinske | Promoted to active roster | | | Before |
| 5/15/2009 | OAK | Lugo | Promoted to active roster | | | Before |
| 5/15/2009 | OAK | Raburn | Demoted to reserve roster | | | Before |
| 5/15/2009 | OAK | Raburn | Promoted to active roster | | | Before |
| 5/15/2009 | OAK | Raburn | Demoted to reserve roster | | | Before |
| 5/15/2009 | OAK | Raburn | Promoted to active roster | | | Before |
| 5/18/2009 | BAL | Isringhausen | Promoted to active roster | | | Before |
| 5/18/2009 | BAL | Sanchez | Demoted to reserve roster | | | Before |
| 5/18/2009 | BOS | Catalanotto | Signed | | | Before |
| 5/18/2009 | BOS | Catalanotto | Promoted to active roster | | | Before |
| 5/18/2009 | BOS | Hansen | Promoted to active roster | | | Before |
| 5/18/2009 | BOS | Kobayashi | Released | | | Before |
| 5/18/2009 | BOS | Reddick | Promoted to active roster | | | Before |
| 5/18/2009 | BOS | Robertson | Promoted to active roster | | | Before |
| 5/18/2009 | BOS | Scott | Demoted to reserve roster | | | Before |
| 5/18/2009 | BOS | Youkilis | Demoted to reserve roster | | | Before |
| 5/18/2009 | DET | Downs | Released | | | Before |
| 5/18/2009 | NYA | Rodriguez | Demoted to reserve roster | | | Before |
| 5/18/2009 | NYA | Rodriguez | Promoted to active roster | | | Before |
| 5/18/2009 | NYA | Ryan | Promoted to active roster | | | Before |
| 5/18/2009 | NYA | Sheffield | Demoted to reserve roster | | | Before |
| 5/18/2009 | SEA | Delgado | Demoted to reserve roster | | | Before |
| 5/18/2009 | SEA | Freese | Demoted to reserve roster | | | Before |
| 5/18/2009 | SEA | Jones | Released | | | Before |
| 5/18/2009 | SEA | Moore | Promoted to active roster | | | Before |
| 5/18/2009 | TB | Jeroloman | Demoted to reserve roster | | | Before |
| 5/18/2009 | TB | Miller | Promoted to active roster | | | Before |
| 5/18/2009 | TEX | Cassel | Released | | | Before |
| 5/18/2009 | TEX | Gardner | Released | | | Before |
| 5/18/2009 | TEX | Gardner | Signed | | | Before |
| 5/18/2009 | TEX | Milton | Signed | | | Before |
| 5/18/2009 | TOR | Ludwick | Demoted to reserve roster | | | Before |
| 5/18/2009 | TOR | Stubbs | Promoted to active roster | | | Before |
| 5/19/2009 | TEX | Santana | Promoted to active roster | | | Before |
| 5/19/2009 | TEX | Schoeneweis | Demoted to reserve roster | | | Before |
| 5/22/2009 | BOS | Carroll | Released | | | Before |
| 5/22/2009 | BOS | Iribarren | Signed | | | Before |
| 5/22/2009 | CHA | Burton | Demoted to reserve roster | | | Before |
| 5/22/2009 | CHA | Mathes | Released | | | Before |
| 5/22/2009 | CHA | Stults | Promoted to active roster | | | Before |
| 5/22/2009 | DET | Downs | Signed | | | Before |
| 5/22/2009 | KC | Albers | Signed | | | Before |
| 5/22/2009 | KC | Brown | Released | | | Before |
| 5/22/2009 | KC | Carpenter | Promoted to active roster | | | Before |
| 5/22/2009 | KC | Hinshaw | Demoted to reserve roster | | | Before |
| 5/22/2009 | OAK | Lowry | Released | | | Before |
| 5/22/2009 | OAK | Miller | Signed | | | Before |
| 5/22/2009 | TB | Jeroloman | Released | | | Before |
| 5/24/2009 | NYA | DeJesus | Acquired via trade | SF | | After |
| 5/24/2009 | NYA | Rowand | Traded away | SF | | After |
| 5/25/2009 | BAL | Balester | Promoted to active roster | | | Before |
| 5/25/2009 | BAL | Kazmir | Demoted to reserve roster | | | Before |
| 5/25/2009 | BAL | Laffey | Demoted to reserve roster | | | Before |
| 5/25/2009 | BAL | Manship | Promoted to active roster | | | Before |
| 5/25/2009 | BOS | Duensing | Promoted to active roster | | | Before |
| 5/25/2009 | BOS | Dukes | Demoted to reserve roster | | | Before |
| 5/25/2009 | BOS | Ford | Released | | | Before |
| 5/25/2009 | BOS | Fulchino | Signed | | | Before |
| 5/25/2009 | BOS | Fulchino | Promoted to active roster | | | Before |
| 5/25/2009 | BOS | Hansen | Demoted to reserve roster | | | Before |
| 5/25/2009 | CHA | Aviles | Demoted to reserve roster | | | Before |
| 5/25/2009 | CHA | Crowe | Demoted to reserve roster | | | Before |
| 5/25/2009 | CHA | Nix | Promoted to active roster | | | Before |
| 5/25/2009 | CHA | Shealy | Promoted to active roster | | | Before |
| 5/25/2009 | CLE | Padilla | Demoted to reserve roster | | | Before |
| 5/25/2009 | CLE | Swarzak | Promoted to active roster | | | Before |
| 5/25/2009 | DET | Ascanio | Promoted to active roster | | | Before |
| 5/25/2009 | DET | Feldman | Signed | | | Before |
| 5/25/2009 | DET | Garcia | Promoted to active roster | | | Before |
| 5/25/2009 | DET | Giese | Demoted to reserve roster | | | Before |
| 5/25/2009 | DET | Pina | Released | | | Before |
| 5/25/2009 | DET | Rogers | Signed | | | Before |
| 5/25/2009 | KC | Albers | Promoted to active roster | | | Before |
| 5/25/2009 | KC | Looper | Demoted to reserve roster | | | Before |
| 5/25/2009 | OAK | Abercrombie | Signed | | | Before |
| 5/25/2009 | OAK | Abercrombie | Promoted to active roster | | | Before |
| 5/25/2009 | OAK | Francisco | Demoted to reserve roster | | | Before |
| 5/25/2009 | OAK | Kennedy | Signed | | | Before |
| 5/25/2009 | OAK | Miller | Released | | | Before |
| 5/25/2009 | SEA | Mickolio | Promoted to active roster | | | Before |
| 5/25/2009 | SEA | Percival | Demoted to reserve roster | | | Before |
| 5/25/2009 | TEX | Harden | Demoted to reserve roster | | | Before |
| 5/25/2009 | TEX | Zambrano | Promoted to active roster | | | Before |
| 5/26/2009 | MIN | Perkins | Demoted to reserve roster | | | Before |
| 5/26/2009 | MIN | Pineiro | Promoted to active roster | | | Before |
| 5/28/2009 | CLE | Byrd | Traded away | PIT | | After |
| 5/28/2009 | CLE | Sowers | Acquired via trade | PIT | | After |
| 5/29/2009 | CHA | Buschmann | Released | | | Before |
| 5/29/2009 | CHA | Crowe | Released | | | Before |
| 5/29/2009 | CHA | Diaz | Signed | | | Before |
| 5/29/2009 | CLE | Jay | Promoted to active roster | | | Before |
| 5/29/2009 | CLE | Sowers | Promoted to active roster | | | Before |
| 5/29/2009 | CLE | Swarzak | Demoted to reserve roster | | | Before |
| 5/29/2009 | DET | Leroux | Signed | | | Before |
| 5/29/2009 | TB | Diaz | Released | | | Before |
| 5/29/2009 | TB | Pina | Signed | | | Before |
| 5/31/2009 | BAL | Beckett | Acquired via trade | SF | | After |
| 5/31/2009 | BAL | Cardenas | Acquired via trade | SF | | After |
| 5/31/2009 | BAL | Kazmir | Traded away | SF | | After |
| 5/31/2009 | BAL | Saltalamacchia | Traded away | SF | | After |
| 5/31/2009 | CHA | Betancourt | Acquired via trade | ARI | | After |
| 5/31/2009 | CHA | Escobar | Traded away | ARI | | After |
| 5/31/2009 | CHA | Hanson | Traded away | ARI | | After |
| 5/31/2009 | CHA | Hart | Acquired via trade | ARI | | After |
| 5/31/2009 | CHA | Iwamura | Acquired via trade | ARI | | After |
| 5/31/2009 | CHA | Jenks | Acquired via trade | ARI | | After |
| 5/31/2009 | CHA | Lyon | Traded away | ARI | | After |
| 5/31/2009 | CHA | Parra | Acquired via trade | ARI | | After |
| 5/31/2009 | CHA | Rosa | Traded away | ARI | | After |
| 6/1/2009 | BAL | Balester | Demoted to reserve roster | | | Before |
| 6/1/2009 | BAL | Bartlett | Demoted to reserve roster | | | Before |
| 6/1/2009 | BAL | Cardenas | Promoted to active roster | | | Before |
| 6/1/2009 | BAL | Morales | Promoted to active roster | | | Before |
| 6/1/2009 | CHA | Coffey | Promoted to active roster | | | Before |
| 6/1/2009 | CHA | Diaz | Promoted to active roster | | | Before |
| 6/1/2009 | CHA | Iwamura | Demoted to reserve roster | | | Before |
| 6/1/2009 | CHA | Montanez | Released | | | Before |
| 6/1/2009 | CHA | Nix | Demoted to reserve roster | | | Before |
| 6/1/2009 | CHA | Stults | Demoted to reserve roster | | | Before |
| 6/1/2009 | CHA | Suppan | Demoted to reserve roster | | | Before |
| 6/1/2009 | CHA | Votto | Demoted to reserve roster | | | Before |
| 6/1/2009 | DET | Garcia | Demoted to reserve roster | | | Before |
| 6/1/2009 | DET | Garcia | Promoted to active roster | | | Before |
| 6/1/2009 | DET | Martis | Demoted to reserve roster | | | Before |
| 6/1/2009 | DET | Reyes | Demoted to reserve roster | | | Before |
| 6/1/2009 | DET | Romo | Promoted to active roster | | | Before |
| 6/1/2009 | OAK | Garciaparra | Released | | | Before |
| 6/1/2009 | OAK | Myers | Demoted to reserve roster | | | Before |
| 6/1/2009 | OAK | Speier | Signed | | | Before |
| 6/1/2009 | OAK | Speier | Promoted to active roster | | | Before |
| 6/1/2009 | SEA | Ankiel | Promoted to active roster | | | Before |
| 6/1/2009 | TEX | Blanco | Promoted to active roster | | | Before |
| 6/1/2009 | TEX | Matsui | Demoted to reserve roster | | | Before |
| 6/1/2009 | TOR | Herrera | Promoted to active roster | | | Before |
| 6/1/2009 | TOR | Ludwick | Promoted to active roster | | | Before |
| 6/1/2009 | TOR | Ruggiano | Demoted to reserve roster | | | Before |
| 6/1/2009 | TOR | Uehara | Demoted to reserve roster | | | Before |
| 6/2/2009 | ANA | Marte | Demoted to reserve roster | | | Before |
| 6/2/2009 | ANA | Rivera | Promoted to active roster | | | Before |
| 6/2/2009 | BOS | Buck | Demoted to reserve roster | | | Before |
| 6/2/2009 | BOS | Quentin | Demoted to reserve roster | | | Before |
| 6/4/2009 | CLE | Joyce | Traded away | SEA | | After |
| 6/4/2009 | CLE | Moss | Acquired via trade | SEA | | After |
| 6/4/2009 | CLE | Sanchez | Acquired via trade | SEA | | After |
| 6/4/2009 | CLE | Sizemore | Traded away | SEA | | After |
| 6/4/2009 | SEA | Joyce | Acquired via trade | CLE | | After |
| 6/4/2009 | SEA | Moss | Traded away | CLE | | After |
| 6/4/2009 | SEA | Sanchez | Traded away | CLE | | After |
| 6/4/2009 | SEA | Sizemore | Acquired via trade | CLE | | After |
| 6/5/2009 | CLE | Duran | Demoted to reserve roster | | | Before |
| 6/5/2009 | CLE | Duran | Promoted to active roster | | | Before |
| 6/5/2009 | CLE | Sanchez | Promoted to active roster | | | Before |
| 6/5/2009 | DET | Leroux | Released | | | Before |
| 6/5/2009 | SEA | Sizemore | Demoted to reserve roster | | | Before |
| 6/5/2009 | TB | Strieby | Signed | | | Before |
| 6/8/2009 | ANA | Lofgren | Signed | | | Before |
| 6/8/2009 | BOS | Catalanotto | Released | | | Before |
| 6/8/2009 | BOS | Dukes | Promoted to active roster | | | Before |
| 6/8/2009 | BOS | Garciaparra | Signed | | | Before |
| 6/8/2009 | BOS | Iribarren | Promoted to active roster | | | Before |
| 6/8/2009 | BOS | Reddick | Demoted to reserve roster | | | Before |
| 6/8/2009 | BOS | Scott | Promoted to active roster | | | Before |
| 6/8/2009 | BOS | Youkilis | Promoted to active roster | | | Before |
| 6/8/2009 | CHA | Burton | Promoted to active roster | | | Before |
| 6/8/2009 | CHA | Ramirez | Demoted to reserve roster | | | Before |
| 6/8/2009 | CLE | Padilla | Promoted to active roster | | | Before |
| 6/8/2009 | CLE | Sanchez | Demoted to reserve roster | | | Before |
| 6/8/2009 | DET | Lofgren | Released | | | Before |
| 6/8/2009 | OAK | Hinske | Released | | | Before |
| 6/8/2009 | SEA | Cabrera | Demoted to reserve roster | | | Before |
| 6/8/2009 | SEA | Walker | Promoted to active roster | | | Before |
| 6/11/2009 | CLE | Bastardo | Acquired via trade | CHN | | After |
| 6/11/2009 | CLE | Guzman | Traded away | CHN | | After |
| 6/11/2009 | CLE | Happ | Traded away | CHN | | After |
| 6/11/2009 | CLE | Huff | Acquired via trade | CHN | | After |
| 6/11/2009 | CLE | Loney | Acquired via trade | CHN | | After |
| 6/11/2009 | CLE | Saunders | Traded away | CHN | | After |
| 6/12/2009 | BAL | Bianchi | Signed | | | Before |
| 6/12/2009 | CHA | Coffey | Demoted to reserve roster | | | Before |
| 6/12/2009 | CHA | Jeroloman | Signed | | | Before |
| 6/12/2009 | CHA | Jeroloman | Promoted to active roster | | | Before |
| 6/12/2009 | DET | Giese | Released | | | Before |
| 6/12/2009 | TB | Bell | Demoted to reserve roster | | | Before |
| 6/12/2009 | TB | Strieby | Promoted to active roster | | | Before |
| 6/14/2009 | CLE | Bailey | Traded away | ARI | | After |
| 6/14/2009 | CLE | Blanks | Acquired via trade | ARI | | After |
| 6/14/2009 | CLE | Delaney | Acquired via trade | ARI | | After |
| 6/15/2009 | BAL | Carrasco | Signed | | | Before |
| 6/15/2009 | BAL | Hedrick | Released | | | Before |
| 6/15/2009 | CLE | Crosby | Released | | | Before |
| 6/15/2009 | CLE | Tuiasosopo | Released | | | Before |
| 6/15/2009 | DET | Downs | Released | | | Before |
| 6/15/2009 | DET | Nieve | Signed | | | Before |
| 6/15/2009 | KC | Sweeney | Demoted to reserve roster | | | Before |
| 6/15/2009 | KC | Venable | Promoted to active roster | | | Before |
| 6/15/2009 | MIN | Bates | Demoted to reserve roster | | | Before |
| 6/15/2009 | MIN | Buscher | Signed | | | Before |
| 6/15/2009 | MIN | Buscher | Promoted to active roster | | | Before |
| 6/15/2009 | MIN | Edmonds | Released | | | Before |
| 6/15/2009 | MIN | Valencia | Demoted to reserve roster | | | Before |
| 6/15/2009 | MIN | Valencia | Promoted to active roster | | | Before |
| 6/15/2009 | OAK | Badenhop | Demoted to reserve roster | | | Before |
| 6/15/2009 | OAK | Raburn | Promoted to active roster | | | Before |
| 6/15/2009 | SEA | Sizemore | Promoted to active roster | | | Before |
| 6/15/2009 | SEA | Thames | Promoted to active roster | | | Before |
| 6/15/2009 | SEA | Walker | Demoted to reserve roster | | | Before |
| 6/15/2009 | TB | Bell | Promoted to active roster | | | Before |
| 6/15/2009 | TB | Pina | Demoted to reserve roster | | | Before |
| 6/15/2009 | TEX | Hernandez | Released | | | Before |
| 6/15/2009 | TEX | Nieves | Signed | | | Before |
| 6/15/2009 | TOR | Herrera | Demoted to reserve roster | | | Before |
| 6/15/2009 | TOR | Uehara | Promoted to active roster | | | Before |
| 6/16/2009 | TEX | Harden | Promoted to active roster | | | Before |
| 6/16/2009 | TEX | Mota | Demoted to reserve roster | | | Before |
| 6/18/2009 | BOS | Byrd | Acquired via trade | PIT | | After |
| 6/18/2009 | BOS | Lowrie | Traded away | PIT | | After |
| 6/18/2009 | BOS | Markakis | Traded away | PIT | | After |
| 6/18/2009 | BOS | Markakis | Acquired via trade | SF | | After |
| 6/18/2009 | BOS | Quentin | Traded away | SF | | After |
| 6/18/2009 | BOS | Rollins | Acquired via trade | PIT | | After |
| 6/18/2009 | BOS | Saltalamacchia | Acquired via trade | SF | | After |
| 6/18/2009 | BOS | Santana | Traded away | SF | | After |
| 6/19/2009 | BOS | Iribarren | Demoted to reserve roster | | | Before |
| 6/19/2009 | BOS | Span | Demoted to reserve roster | | | Before |
| 6/19/2009 | CLE | Crisp | Demoted to reserve roster | | | Before |
| 6/19/2009 | CLE | Powell | Promoted to active roster | | | Before |
| 6/19/2009 | DET | McGehee | Signed | | | Before |
| 6/19/2009 | MIN | Betancourt | Demoted to reserve roster | | | Before |
| 6/19/2009 | MIN | Buscher | Promoted to active roster | | | Before |
| 6/19/2009 | SEA | Percival | Released | | | Before |
| 6/19/2009 | SEA | Snelling | Signed | | | Before |
| 6/22/2009 | BAL | Bartlett | Promoted to active roster | | | Before |
| 6/22/2009 | BAL | Carrasco | Promoted to active roster | | | Before |
| 6/22/2009 | BAL | Hoffpauir | Demoted to reserve roster | | | Before |
| 6/22/2009 | BAL | Isringhausen | Demoted to reserve roster | | | Before |
| 6/22/2009 | BAL | Sanchez | Promoted to active roster | | | Before |
| 6/22/2009 | BOS | Garciaparra | Promoted to active roster | | | Before |
| 6/22/2009 | BOS | Scales | Demoted to reserve roster | | | Before |
| 6/22/2009 | CHA | Jeroloman | Demoted to reserve roster | | | Before |
| 6/22/2009 | CHA | Niemann | Demoted to reserve roster | | | Before |
| 6/22/2009 | CHA | Ramirez | Promoted to active roster | | | Before |
| 6/22/2009 | CHA | Suppan | Promoted to active roster | | | Before |
| 6/22/2009 | DET | Downs | Signed | | | Before |
| 6/22/2009 | DET | Garcia | Demoted to reserve roster | | | Before |
| 6/22/2009 | DET | Nieve | Demoted to reserve roster | | | Before |
| 6/22/2009 | MIN | Bates | Demoted to reserve roster | | | Before |
| 6/22/2009 | MIN | Correia | Signed | | | Before |
| 6/22/2009 | MIN | Correia | Promoted to active roster | | | Before |
| 6/22/2009 | OAK | Badenhop | Promoted to active roster | | | Before |
| 6/22/2009 | OAK | Raburn | Demoted to reserve roster | | | Before |
| 6/22/2009 | SEA | Hampton | Demoted to reserve roster | | | Before |
| 6/23/2009 | OAK | Badenhop | Promoted to active roster | | | Before |
| 6/23/2009 | OAK | Raburn | Demoted to reserve roster | | | Before |
| 6/25/2009 | BOS | Bedard | Acquired via trade | SF | | After |
| 6/25/2009 | BOS | Fulchino | Traded away | SF | | After |
| 6/25/2009 | BOS | Soriano | Acquired via trade | SF | | After |
| 6/25/2009 | BOS | Webb | Traded away | SF | | After |
| 6/25/2009 | KC | Diaz | Acquired via trade | WAS | | After |
| 6/25/2009 | KC | Masset | Acquired via trade | WAS | | After |
| 6/25/2009 | KC | Masterson | Traded away | WAS | | After |
| 6/25/2009 | KC | Soriano | Acquired via trade | WAS | | After |
| 6/25/2009 | KC | Spilborghs | Traded away | WAS | | After |
| 6/25/2009 | KC | Sweeney | Traded away | WAS | | After |
| 6/26/2009 | BOS | Diamond | Released | | | Before |
| 6/26/2009 | BOS | Hansen | Released | | | Before |
| 6/26/2009 | BOS | Scales | Released | | | Before |
| 6/26/2009 | CHA | Jeroloman | Released | | | Before |
| 6/26/2009 | CHA | Pina | Signed | | | Before |
| 6/26/2009 | KC | Diaz | Promoted to active roster | | | Before |
| 6/26/2009 | KC | Looper | Promoted to active roster | | | Before |
| 6/26/2009 | KC | Venable | Demoted to reserve roster | | | Before |
| 6/26/2009 | TB | Pina | Released | | | Before |
| 6/29/2009 | BAL | Isringhausen | Released | | | Before |
| 6/29/2009 | BOS | Murphy | Released | | | Before |
| 6/29/2009 | BOS | Willis | Signed | | | Before |
| 6/29/2009 | CHA | Betancourt | Demoted to reserve roster | | | Before |
| 6/29/2009 | CHA | Coffey | Promoted to active roster | | | Before |
| 6/29/2009 | CHA | Lindstrom | Demoted to reserve roster | | | Before |
| 6/29/2009 | CHA | Votto | Promoted to active roster | | | Before |
| 6/29/2009 | CLE | Duran | Demoted to reserve roster | | | Before |
| 6/29/2009 | CLE | Huffman | Promoted to active roster | | | Before |
| 6/29/2009 | KC | Rivera | Released | | | Before |
| 6/29/2009 | NYA | Bruney | Promoted to active roster | | | Before |
| 6/29/2009 | NYA | Farnsworth | Demoted to reserve roster | | | Before |
| 6/29/2009 | SEA | Anderson | Demoted to reserve roster | | | Before |
| 6/29/2009 | TB | Bell | Promoted to active roster | | | Before |
| 6/29/2009 | TB | Garrison | Signed | | | Before |
| 6/29/2009 | TOR | Smoltz | Promoted to active roster | | | Before |
| 6/29/2009 | TOR | Uehara | Demoted to reserve roster | | | Before |
| 6/30/2009 | BOS | Giles | Demoted to reserve roster | | | Before |
| 6/30/2009 | NYA | Bruney | Promoted to active roster | | | Before |
| 6/30/2009 | NYA | Farnsworth | Demoted to reserve roster | | | Before |
| 6/30/2009 | TEX | Santana | Demoted to reserve roster | | | Before |
| 7/2/2009 | BAL | Beckett | Traded away | PIT | | After |
| 7/2/2009 | BAL | Liriano | Acquired via trade | PIT | | After |
| 7/2/2009 | BAL | Lowrie | Acquired via trade | PIT | | After |
| 7/2/2009 | BAL | Marshall | Traded away | PIT | | After |
| 7/2/2009 | BAL | Shoppach | Traded away | PIT | | After |
| 7/2/2009 | BOS | Greinke | Traded away | SF | | After |
| 7/2/2009 | BOS | Kazmir | Acquired via trade | SF | | After |
| 7/2/2009 | DET | Downs | Traded away | PIT | | After |
| 7/2/2009 | KC | Aardsma | Traded away | PHI | | After |
| 7/2/2009 | KC | Davis | Traded away | PHI | | After |
| 7/2/2009 | KC | Dempster | Acquired via trade | NYN | | After |
| 7/2/2009 | KC | Dotel | Acquired via trade | PHI | | After |
| 7/2/2009 | KC | Hanigan | Traded away | NYN | | After |
| 7/2/2009 | KC | Litsch | Traded away | NYN | | After |
| 7/2/2009 | KC | Lowe | Acquired via trade | PHI | | After |
| 7/2/2009 | KC | Masset | Traded away | PHI | | After |
| 7/2/2009 | KC | Moylan | Acquired via trade | NYN | | After |
| 7/2/2009 | KC | Oliver | Acquired via trade | PHI | | After |
| 7/2/2009 | KC | Saunders | Traded away | NYN | | After |
| 7/2/2009 | SEA | DeRosa | Traded away | WAS | | After |
| 7/2/2009 | SEA | Walden | Acquired via trade | WAS | | After |
| 7/3/2009 | BAL | Hoffpauir | Promoted to active roster | | | Before |
| 7/3/2009 | BAL | Olson | Promoted to active roster | | | Before |
| 7/3/2009 | BOS | Buck | Promoted to active roster | | | Before |
| 7/3/2009 | BOS | Reddick | Promoted to active roster | | | Before |
| 7/3/2009 | BOS | Span | Demoted to reserve roster | | | Before |
| 7/3/2009 | BOS | Span | Promoted to active roster | | | Before |
| 7/3/2009 | DET | Garcia | Released | | | Before |
| 7/3/2009 | KC | Albers | Demoted to reserve roster | | | Before |
| 7/3/2009 | KC | Dotel | Demoted to reserve roster | | | Before |
| 7/3/2009 | KC | Exposito | Promoted to active roster | | | Before |
| 7/3/2009 | KC | Wolfe | Demoted to reserve roster | | | Before |
| 7/3/2009 | SEA | Snelling | Released | | | Before |
| 7/3/2009 | SEA | Thomas | Promoted to active roster | | | Before |
| 7/3/2009 | TB | Mills | Demoted to reserve roster | | | Before |
| 7/3/2009 | TB | Richard | Demoted to reserve roster | | | Before |
| 7/3/2009 | TB | Snyder | Demoted to reserve roster | | | Before |
| 7/3/2009 | TB | Strieby | Demoted to reserve roster | | | Before |
| 7/3/2009 | TB | Weglarz | Demoted to reserve roster | | | Before |
| 7/3/2009 | TOR | Ruggiano | Released | | | Before |
| 7/6/2009 | BAL | Balester | Promoted to active roster | | | Before |
| 7/6/2009 | BAL | Slowey | Demoted to reserve roster | | | Before |
| 7/6/2009 | BOS | Lowell | Demoted to reserve roster | | | Before |
| 7/6/2009 | BOS | Span | Promoted to active roster | | | Before |
| 7/6/2009 | CHA | Aviles | Released | | | Before |
| 7/6/2009 | SEA | Cabrera | Promoted to active roster | | | Before |
| 7/6/2009 | SEA | Hampton | Promoted to active roster | | | Before |
| 7/6/2009 | SEA | Mickolio | Demoted to reserve roster | | | Before |
| 7/6/2009 | SEA | Rowland-Smith | Promoted to active roster | | | Before |
| 7/6/2009 | SEA | Thomas | Demoted to reserve roster | | | Before |
| 7/7/2009 | NYA | Harris | Demoted to reserve roster | | | Before |
| 7/7/2009 | NYA | Ramirez | Promoted to active roster | | | Before |
| 7/7/2009 | TEX | Byrnes | Demoted to reserve roster | | | Before |
| 7/9/2009 | KC | Wigginton | Traded away | WAS | | After |
| 7/9/2009 | KC | Yabu | Acquired via trade | WAS | | After |
| 7/9/2009 | OAK | Raburn | Traded away | STL | | After |
| 7/9/2009 | OAK | Wells | Acquired via trade | STL | | After |
| 7/10/2009 | ANA | McCarthy | Demoted to reserve roster | | | Before |
| 7/10/2009 | BAL | Coste | Signed | | | Before |
| 7/10/2009 | CHA | Alfonzo | Signed | | | Before |
| 7/10/2009 | OAK | Mitre | Signed | | | Before |
| 7/11/2009 | ANA | Reyes | Demoted to reserve roster | | | Before |
| 7/16/2009 | BAL | Balester | Demoted to reserve roster | | | Before |
| 7/16/2009 | BAL | Coste | Promoted to active roster | | | Before |
| 7/16/2009 | BAL | Hoffpauir | Demoted to reserve roster | | | Before |
| 7/16/2009 | BAL | Laffey | Promoted to active roster | | | Before |
| 7/16/2009 | BAL | Lowrie | Promoted to active roster | | | Before |
| 7/16/2009 | BAL | Tabata | Demoted to reserve roster | | | Before |
| 7/16/2009 | BOS | Bedard | Promoted to active roster | | | Before |
| 7/16/2009 | BOS | Duensing | Demoted to reserve roster | | | Before |
| 7/16/2009 | CHA | Alfonzo | Promoted to active roster | | | Before |
| 7/16/2009 | CHA | Danks | Demoted to reserve roster | | | Before |
| 7/16/2009 | CHA | Danks | Promoted to active roster | | | Before |
| 7/16/2009 | CHA | Nix | Promoted to active roster | | | Before |
| 7/16/2009 | CHA | Ramirez | Demoted to reserve roster | | | Before |
| 7/16/2009 | CHA | Reimold | Demoted to reserve roster | | | Before |
| 7/16/2009 | CLE | Lopez | Released | | | Before |
| 7/16/2009 | CLE | Martis | Signed | | | Before |
| 7/16/2009 | CLE | Martis | Promoted to active roster | | | Before |
| 7/16/2009 | CLE | Swarzak | Promoted to active roster | | | Before |
| 7/16/2009 | CLE | Valdez | Demoted to reserve roster | | | Before |
| 7/16/2009 | CLE | Veal | Released | | | Before |
| 7/16/2009 | DET | Martis | Released | | | Before |
| 7/16/2009 | DET | Thomas | Signed | | | Before |
| 7/16/2009 | KC | Dempster | Demoted to reserve roster | | | Before |
| 7/16/2009 | KC | Feliz | Promoted to active roster | | | Before |
| 7/16/2009 | KC | Yabu | Promoted to active roster | | | Before |
| 7/16/2009 | MIN | Embree | Demoted to reserve roster | | | Before |
| 7/16/2009 | MIN | Perkins | Promoted to active roster | | | Before |
| 7/16/2009 | TB | Garrison | Released | | | Before |
| 7/16/2009 | TB | Walters | Signed | | | Before |
| 7/16/2009 | TEX | Blanco | Demoted to reserve roster | | | Before |
| 7/16/2009 | TEX | Matsui | Promoted to active roster | | | Before |
| 7/16/2009 | TEX | Nix | Promoted to active roster | | | Before |
| 7/16/2009 | TEX | Santana | Promoted to active roster | | | Before |
| 7/19/2009 | ANA | Bourjos | Acquired via trade | WAS | | After |
| 7/19/2009 | ANA | Marrero | Traded away | WAS | | After |
| 7/20/2009 | BOS | Lowell | Promoted to active roster | | | Before |
| 7/20/2009 | BOS | Waring | Demoted to reserve roster | | | Before |
| 7/20/2009 | DET | Gordon | Promoted to active roster | | | Before |
| 7/20/2009 | DET | Sampson | Demoted to reserve roster | | | Before |
| 7/20/2009 | NYA | Glavine | Released | | | Before |
| 7/20/2009 | OAK | Meche | Demoted to reserve roster | | | Before |
| 7/20/2009 | OAK | Speier | Promoted to active roster | | | Before |
| 7/20/2009 | TOR | Herrera | Promoted to active roster | | | Before |
| 7/20/2009 | TOR | Sonnanstine | Demoted to reserve roster | | | Before |
| 7/21/2009 | TEX | Mota | Promoted to active roster | | | Before |
| 7/21/2009 | TEX | Wade | Demoted to reserve roster | | | Before |
| 7/23/2009 | DET | Martinez | Acquired via trade | ATL | | After |
| 7/24/2009 | CHA | Niemann | Promoted to active roster | | | Before |
| 7/24/2009 | CHA | Suppan | Demoted to reserve roster | | | Before |
| 7/24/2009 | TB | Ciriaco | Signed | | | Before |
| 7/24/2009 | TB | League | Demoted to reserve roster | | | Before |
| 7/24/2009 | TB | Richard | Promoted to active roster | | | Before |
| 7/24/2009 | TB | Walters | Promoted to active roster | | | Before |
| 7/26/2009 | TB | League | Traded away | ARI | | After |
| 7/27/2009 | CHA | Armstrong | Demoted to reserve roster | | | Before |
| 7/27/2009 | CHA | Betancourt | Promoted to active roster | | | Before |
| 7/27/2009 | CHA | Burton | Demoted to reserve roster | | | Before |
| 7/27/2009 | CHA | Diaz | Demoted to reserve roster | | | Before |
| 7/27/2009 | CHA | Nunez | Promoted to active roster | | | Before |
| 7/27/2009 | CHA | Ramirez | Promoted to active roster | | | Before |
| 7/27/2009 | CHA | Reimold | Promoted to active roster | | | Before |
| 7/27/2009 | CHA | Shealy | Demoted to reserve roster | | | Before |
| 7/27/2009 | CLE | Gallagher | Demoted to reserve roster | | | Before |
| 7/27/2009 | CLE | Schmidt | Promoted to active roster | | | Before |
| 7/27/2009 | MIN | Barajas | Promoted to active roster | | | Before |
| 7/27/2009 | MIN | Guillen | Demoted to reserve roster | | | Before |
| 7/27/2009 | NYA | Gardner | Demoted to reserve roster | | | Before |
| 7/27/2009 | NYA | Harris | Promoted to active roster | | | Before |
| 7/27/2009 | OAK | Cordero | Promoted to active roster | | | Before |
| 7/27/2009 | OAK | Giambi | Demoted to reserve roster | | | Before |
| 7/27/2009 | TB | Hunter | Demoted to reserve roster | | | Before |
| 7/27/2009 | TB | Weglarz | Promoted to active roster | | | Before |
| 7/27/2009 | TOR | Escobar | Demoted to reserve roster | | | Before |
| 7/27/2009 | TOR | Guillen | Promoted to active roster | | | Before |
| 7/27/2009 | TOR | Herrera | Demoted to reserve roster | | | Before |
| 7/27/2009 | TOR | Herrera | Promoted to active roster | | | Before |
| 7/27/2009 | TOR | Sonnanstine | Promoted to active roster | | | Before |
| 7/27/2009 | TOR | Wakefield | Demoted to reserve roster | | | Before |
| 7/30/2009 | KC | Yabu | Demoted to reserve roster | | | Before |
| 7/30/2009 | KC | Brantley | Acquired via trade | STL | | After |
| 7/30/2009 | KC | Capps | Acquired via trade | STL | | After |
| 7/30/2009 | KC | Cecil | Acquired via trade | STL | | After |
| 7/30/2009 | KC | Jurrjens | Traded away | STL | | After |
| 7/30/2009 | KC | Lannan | Acquired via trade | STL | | After |
| 7/30/2009 | KC | Willingham | Traded away | STL | | After |
| 7/30/2009 | SEA | Meredith | Traded away | COL | | After |
| 7/31/2009 | CHA | Nippert | Signed | | | Before |
| 7/31/2009 | CHA | Shealy | Released | | | Before |
| 7/31/2009 | CLE | Dickerson | Demoted to reserve roster | | | Before |
| 7/31/2009 | CLE | Langerhans | Signed | | | Before |
| 7/31/2009 | CLE | Langerhans | Promoted to active roster | | | Before |
| 7/31/2009 | DET | Nieve | Released | | | Before |
| 7/31/2009 | KC | Capps | Promoted to active roster | | | Before |
| 7/31/2009 | KC | Grudzielanek | Promoted to active roster | | | Before |
| 7/31/2009 | KC | Moylan | Demoted to reserve roster | | | Before |
| 7/31/2009 | KC | Negrych | Released | | | Before |
| 7/31/2009 | SEA | Marek | Released | | | Before |
| 7/31/2009 | TB | Hunter | Released | | | Before |
| 8/2/2009 | BAL | Greene | Signed | | | Before |
| 8/2/2009 | BAL | Ottavino | Released | | | Before |
| 8/2/2009 | TB | Brown | Signed | | | Before |
| 8/3/2009 | BAL | Barton | Demoted to reserve roster | | | Before |
| 8/3/2009 | BAL | Hoffpauir | Promoted to active roster | | | Before |
| 8/3/2009 | BOS | Bedard | Demoted to reserve roster | | | Before |
| 8/3/2009 | BOS | Duensing | Promoted to active roster | | | Before |
| 8/3/2009 | BOS | Jaramillo | Promoted to active roster | | | Before |
| 8/3/2009 | BOS | Saltalamacchia | Demoted to reserve roster | | | Before |
| 8/3/2009 | CHA | Diaz | Promoted to active roster | | | Before |
| 8/3/2009 | CHA | Hart | Demoted to reserve roster | | | Before |
| 8/3/2009 | CHA | Nippert | Promoted to active roster | | | Before |
| 8/3/2009 | CHA | Schierholtz | Demoted to reserve roster | | | Before |
| 8/3/2009 | DET | Sampson | Promoted to active roster | | | Before |
| 8/3/2009 | KC | Dempster | Promoted to active roster | | | Before |
| 8/3/2009 | KC | Looper | Demoted to reserve roster | | | Before |
| 8/3/2009 | MIN | Bates | Promoted to active roster | | | Before |
| 8/3/2009 | MIN | Betancourt | Promoted to active roster | | | Before |
| 8/3/2009 | MIN | Correia | Demoted to reserve roster | | | Before |
| 8/3/2009 | MIN | Kottaras | Demoted to reserve roster | | | Before |
| 8/3/2009 | SEA | Freese | Promoted to active roster | | | Before |
| 8/3/2009 | SEA | Sizemore | Demoted to reserve roster | | | Before |
| 8/3/2009 | SEA | Walker | Promoted to active roster | | | Before |
| 8/3/2009 | TOR | Fisher | Promoted to active roster | | | Before |
| 8/3/2009 | TOR | Hawkins | Demoted to reserve roster | | | Before |
| 8/9/2009 | ANA | Kennedy | Acquired via trade | BAL | | After |
| 8/9/2009 | ANA | Lind | Traded away | BAL | | After |
| 8/9/2009 | ANA | Poreda | Acquired via trade | BAL | | After |
| 8/9/2009 | ANA | Tabata | Acquired via trade | BAL | | After |
| 8/9/2009 | BAL | Kennedy | Traded away | ANA | | After |
| 8/9/2009 | BAL | Lind | Acquired via trade | ANA | | After |
| 8/9/2009 | BAL | Poreda | Traded away | ANA | | After |
| 8/9/2009 | BAL | Tabata | Traded away | ANA | | After |
| 8/9/2009 | KC | Moylan | Traded away | STL | | After |
| 8/9/2009 | KC | Wellemeyer | Acquired via trade | STL | | After |
| 8/10/2009 | CLE | Colome | Demoted to reserve roster | | | Before |
| 8/10/2009 | CLE | Lincoln | Promoted to active roster | | | Before |
| 8/10/2009 | CLE | Sanchez | Promoted to active roster | | | Before |
| 8/10/2009 | CLE | Schmidt | Demoted to reserve roster | | | Before |
| 8/10/2009 | DET | Braden | Demoted to reserve roster | | | Before |
| 8/10/2009 | NYA | Baker | Promoted to active roster | | | Before |
| 8/10/2009 | NYA | Harris | Demoted to reserve roster | | | Before |
| 8/10/2009 | TOR | Herrera | Demoted to reserve roster | | | Before |
| 8/10/2009 | TOR | Herrera | Promoted to active roster | | | Before |
| 8/10/2009 | TOR | Shouse | Signed | | | Before |
| 8/10/2009 | TOR | Shouse | Promoted to active roster | | | Before |
| 8/10/2009 | TOR | Slaten | Demoted to reserve roster | | | Before |
| 8/11/2009 | KC | Eckstein | Demoted to reserve roster | | | Before |
| 8/11/2009 | KC | Wellemeyer | Promoted to active roster | | | Before |
| 8/11/2009 | OAK | Badenhop | Demoted to reserve roster | | | Before |
| 8/11/2009 | TEX | Zambrano | Demoted to reserve roster | | | Before |
| 8/13/2009 | ANA | Carpenter | Traded away | NYN | | After |
| 8/13/2009 | ANA | Marte | Traded away | NYN | | After |
| 8/13/2009 | ANA | Saunders | Acquired via trade | NYN | | After |
| 8/14/2009 | ANA | Adenhart | Released | | | Before |
| 8/14/2009 | ANA | Mathis | Signed | | | Before |
| 8/14/2009 | ANA | Ortega | Released | | | Before |
| 8/14/2009 | MIN | Mathis | Released | | | Before |
| 8/14/2009 | MIN | Oeltjen | Signed | | | Before |
| 8/14/2009 | MIN | Reynolds | Released | | | Before |
| 8/14/2009 | OAK | Badenhop | Released | | | Before |
| 8/14/2009 | OAK | Martinez | Signed | | | Before |
| 8/14/2009 | TB | Outman | Signed | | | Before |
| 8/16/2009 | CHA | Cecil | Acquired via trade | KC | | After |
| 8/16/2009 | CHA | Nolasco | Traded away | KC | | After |
| 8/16/2009 | KC | Cecil | Traded away | CHA | | After |
| 8/16/2009 | KC | Nolasco | Acquired via trade | CHA | | After |
| 8/16/2009 | SEA | Burnett | Traded away | FLA | | After |
| 8/16/2009 | SEA | Hampton | Traded away | FLA | | After |
| 8/16/2009 | SEA | Johnson | Traded away | FLA | | After |
| 8/16/2009 | SEA | Sheets | Acquired via trade | FLA | | After |
| 8/16/2009 | SEA | Troncoso | Acquired via trade | FLA | | After |
| 8/17/2009 | BAL | Greene | Promoted to active roster | | | Before |
| 8/17/2009 | BAL | Hoffpauir | Demoted to reserve roster | | | Before |
| 8/17/2009 | BAL | Humber | Promoted to active roster | | | Before |
| 8/17/2009 | BAL | Lowrie | Demoted to reserve roster | | | Before |
| 8/17/2009 | DET | Martinez | Promoted to active roster | | | Before |
| 8/17/2009 | MIN | Correia | Promoted to active roster | | | Before |
| 8/17/2009 | MIN | Perkins | Demoted to reserve roster | | | Before |
| 8/17/2009 | NYA | Feliz | Promoted to active roster | | | Before |
| 8/17/2009 | NYA | Melancon | Demoted to reserve roster | | | Before |
| 8/17/2009 | NYA | Melancon | Promoted to active roster | | | Before |
| 8/17/2009 | NYA | Ryan | Demoted to reserve roster | | | Before |
| 8/17/2009 | OAK | Martinez | Promoted to active roster | | | Before |
| 8/17/2009 | OAK | Meche | Promoted to active roster | | | Before |
| 8/17/2009 | OAK | Speier | Demoted to reserve roster | | | Before |
| 8/17/2009 | SEA | Mickolio | Promoted to active roster | | | Before |
| 8/17/2009 | SEA | Mock | Promoted to active roster | | | Before |
| 8/17/2009 | SEA | Troncoso | Promoted to active roster | | | Before |
| 8/17/2009 | TB | Mills | Promoted to active roster | | | Before |
| 8/17/2009 | TB | Snyder | Promoted to active roster | | | Before |
| 8/17/2009 | TB | Strieby | Promoted to active roster | | | Before |
| 8/17/2009 | TOR | Hawkins | Promoted to active roster | | | Before |
| 8/17/2009 | TOR | Herrera | Demoted to reserve roster | | | Before |
| 8/18/2009 | KC | Wellemeyer | Demoted to reserve roster | | | Before |
| 8/20/2009 | KC | DeLome | Traded away | MIN | | After |
| 8/20/2009 | KC | Wagner | Acquired via trade | MIN | | After |
| 8/20/2009 | MIN | DeLome | Acquired via trade | KC | | After |
| 8/20/2009 | MIN | Wagner | Traded away | KC | | After |
| 8/21/2009 | BAL | Anderson | Signed | | | Before |
| 8/21/2009 | CHA | Cruz | Demoted to reserve roster | | | Before |
| 8/21/2009 | CHA | Schierholtz | Promoted to active roster | | | Before |
| 8/21/2009 | MIN | Wood | Released | | | Before |
| 8/21/2009 | TB | Ciriaco | Released | | | Before |
| 8/21/2009 | TB | Desmond | Signed | | | Before |
| 8/23/2009 | ANA | Clement | Traded away | CHN | | After |
| 8/23/2009 | ANA | McCutchen | Traded away | CHN | | After |
| 8/23/2009 | ANA | Paulino | Traded away | CHN | | After |
| 8/23/2009 | ANA | Saunders | Acquired via trade | CHN | | After |
| 8/24/2009 | ANA | Bonifacio | Signed | | | Before |
| 8/24/2009 | ANA | Lubanski | Released | | | Before |
| 8/24/2009 | ANA | Luna | Signed | | | Before |
| 8/24/2009 | ANA | Molina | Signed | | | Before |
| 8/24/2009 | BAL | Balester | Promoted to active roster | | | Before |
| 8/24/2009 | BAL | Liriano | Demoted to reserve roster | | | Before |
| 8/24/2009 | CHA | Cecil | Demoted to reserve roster | | | Before |
| 8/24/2009 | CHA | Cruz | Promoted to active roster | | | Before |
| 8/24/2009 | CHA | Diaz | Demoted to reserve roster | | | Before |
| 8/24/2009 | CHA | Poveda | Promoted to active roster | | | Before |
| 8/24/2009 | CHA | Suppan | Released | | | Before |
| 8/24/2009 | DET | Schneider | Signed | | | Before |
| 8/24/2009 | NYA | Farnsworth | Released | | | Before |
| 8/24/2009 | OAK | Badenhop | Signed | | | Before |
| 8/24/2009 | OAK | Giambi | Released | | | Before |
| 8/24/2009 | OAK | Hinske | Signed | | | Before |
| 8/24/2009 | OAK | Speier | Released | | | Before |
| 8/24/2009 | TB | Brown | Promoted to active roster | | | Before |
| 8/24/2009 | TB | Guzman | Demoted to reserve roster | | | Before |
| 8/24/2009 | TB | Guzman | Promoted to active roster | | | Before |
| 8/24/2009 | TB | Simmons | Demoted to reserve roster | | | Before |
| 8/24/2009 | TOR | Fisher | Demoted to reserve roster | | | Before |
| 8/24/2009 | TOR | Snell | Promoted to active roster | | | Before |
| 8/25/2009 | KC | Eckstein | Promoted to active roster | | | Before |
| 8/25/2009 | KC | Grudzielanek | Demoted to reserve roster | | | Before |
| 8/25/2009 | KC | Wagner | Promoted to active roster | | | Before |
| 8/25/2009 | TEX | Blanco | Promoted to active roster | | | Before |
| 8/25/2009 | TEX | McLouth | Demoted to reserve roster | | | Before |
| 8/25/2009 | TEX | Zambrano | Promoted to active roster | | | Before |
| 8/27/2009 | BOS | Guthrie | Traded away | KC | | After |
| 8/27/2009 | BOS | Kazmir | Traded away | SF | | After |
| 8/27/2009 | BOS | Looper | Acquired via trade | KC | | After |
| 8/27/2009 | BOS | Rollins | Traded away | SF | | After |
| 8/27/2009 | BOS | Scutaro | Acquired via trade | SF | | After |
| 8/27/2009 | BOS | Webb | Acquired via trade | SF | | After |
| 8/27/2009 | CLE | Crisp | Traded away | SF | | After |
| 8/27/2009 | CLE | Rowand | Acquired via trade | SF | | After |
| 8/27/2009 | DET | Furcal | Acquired via trade | STL | | After |
| 8/27/2009 | DET | McGehee | Traded away | STL | | After |
| 8/27/2009 | DET | Redmond | Acquired via trade | STL | | After |
| 8/27/2009 | KC | Bonderman | Acquired via trade | SF | | After |
| 8/27/2009 | KC | Dotel | Traded away | NYA | | After |
| 8/27/2009 | KC | Flores | Acquired via trade | SF | | After |
| 8/27/2009 | KC | Guthrie | Acquired via trade | BOS | | After |
| 8/27/2009 | KC | Looper | Traded away | BOS | | After |
| 8/27/2009 | KC | Nolasco | Traded away | SF | | After |
| 8/27/2009 | NYA | Dotel | Acquired via trade | KC | | After |
| 8/27/2009 | NYA | Marte | Acquired via trade | NYN | | After |
| 8/27/2009 | NYA | Santeliz | Traded away | NYN | | After |
| 8/28/2009 | ANA | Johjima | Signed | | | Before |
| 8/28/2009 | CLE | Colome | Released | | | Before |
| 8/28/2009 | CLE | Tuiasosopo | Signed | | | Before |
| 8/28/2009 | CLE | Tuiasosopo | Demoted to reserve roster | | | Before |
| 8/28/2009 | DET | Schneider | Released | | | Before |
| 8/28/2009 | NYA | Harris | Released | | | Before |
| 8/28/2009 | OAK | Abercrombie | Demoted to reserve roster | | | Before |
| 8/28/2009 | OAK | Giambi | Signed | | | Before |
| 8/28/2009 | OAK | Martinez | Released | | | Before |
| 8/28/2009 | OAK | Wells | Promoted to active roster | | | Before |
| 8/28/2009 | SEA | Johnson | Signed | | | Before |
| 8/28/2009 | SEA | Thomas | Released | | | Before |
| 8/30/2009 | OAK | Bay | Acquired via trade | SD | | After |
| 8/30/2009 | OAK | Villalona | Traded away | SD | | After |
| 8/31/2009 | BAL | Anderson | Released | | | Before |
| 8/31/2009 | BAL | Anderson | Promoted to active roster | | | Before |
| 8/31/2009 | BAL | Barton | Promoted to active roster | | | Before |
| 8/31/2009 | BAL | Hoffpauir | Promoted to active roster | | | Before |
| 8/31/2009 | BAL | McGee | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Armstrong | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Cecil | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Diaz | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Iwamura | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Lindstrom | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Pina | Promoted to active roster | | | Before |
| 8/31/2009 | CHA | Stults | Promoted to active roster | | | Before |
| 8/31/2009 | CLE | Duran | Released | | | Before |
| 8/31/2009 | CLE | Martinez | Signed | | | Before |
| 8/31/2009 | DET | Redmond | Released | | | Before |
| 8/31/2009 | NYA | Borbon | Promoted to active roster | | | Before |
| 8/31/2009 | NYA | Dotel | Promoted to active roster | | | Before |
| 8/31/2009 | NYA | Jones | Promoted to active roster | | | Before |
| 8/31/2009 | NYA | Melancon | Promoted to active roster | | | Before |
| 8/31/2009 | NYA | Sheffield | Promoted to active roster | | | Before |
| 8/31/2009 | OAK | Abercrombie | Promoted to active roster | | | Before |
| 8/31/2009 | OAK | Francisco | Promoted to active roster | | | Before |
| 8/31/2009 | OAK | Hinske | Promoted to active roster | | | Before |
| 8/31/2009 | OAK | Lugo | Promoted to active roster | | | Before |
| 8/31/2009 | OAK | Mulvey | Promoted to active roster | | | Before |
| 8/31/2009 | OAK | Wagner | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Branyan | Demoted to reserve roster | | | Before |
| 8/31/2009 | TOR | Escobar | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Fisher | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Herrera | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Salazar | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Santana | Demoted to reserve roster | | | Before |
| 8/31/2009 | TOR | Slaten | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Wakefield | Promoted to active roster | | | Before |
| 8/31/2009 | TOR | Zaun | Promoted to active roster | | | Before |
| 9/3/2009 | BAL | Anderson | Acquired via trade | ATL | | After |
| 9/3/2009 | BAL | Balentien | Traded away | CLE | | After |
| 9/3/2009 | BAL | Cardenas | Traded away | CLE | | After |
| 9/3/2009 | BAL | Jay | Acquired via trade | CLE | | After |
| 9/3/2009 | BAL | LaRoche | Acquired via trade | ATL | | After |
| 9/3/2009 | BAL | Liriano | Traded away | ATL | | After |
| 9/3/2009 | BAL | Loney | Acquired via trade | CLE | | After |
| 9/3/2009 | BAL | McGee | Traded away | CLE | | After |
| 9/3/2009 | BOS | Balfour | Traded away | FLA | | After |
| 9/3/2009 | BOS | Buehrle | Traded away | FLA | | After |
| 9/3/2009 | BOS | Dukes | Traded away | FLA | | After |
| 9/3/2009 | BOS | Gonzalez | Acquired via trade | FLA | | After |
| 9/3/2009 | BOS | Hairston | Traded away | FLA | | After |
| 9/3/2009 | BOS | Hairston | Acquired via trade | FLA | | After |
| 9/3/2009 | BOS | Hairston | Acquired via trade | FLA | | After |
| 9/3/2009 | BOS | Pence | Acquired via trade | FLA | | After |
| 9/3/2009 | BOS | Span | Traded away | FLA | | After |
| 9/3/2009 | CLE | Balentien | Acquired via trade | BAL | | After |
| 9/3/2009 | CLE | Cardenas | Acquired via trade | BAL | | After |
| 9/3/2009 | CLE | Jay | Traded away | BAL | | After |
| 9/3/2009 | CLE | Loney | Traded away | BAL | | After |
| 9/3/2009 | CLE | McGee | Acquired via trade | BAL | | After |
| 9/4/2009 | ANA | Antonelli | Signed | | | Before |
| 9/4/2009 | BAL | Humber | Released | | | Before |
| 9/4/2009 | CLE | Blanks | Demoted to reserve roster | | | Before |
| 9/4/2009 | CLE | Burriss | Released | | | Before |
| 9/4/2009 | CLE | Crowe | Signed | | | Before |
| 9/4/2009 | CLE | Dickerson | Promoted to active roster | | | Before |
| 9/4/2009 | CLE | McGee | Demoted to reserve roster | | | Before |
| 9/4/2009 | MIN | Duncan | Signed | | | Before |
| 9/4/2009 | MIN | Oeltjen | Released | | | Before |
| 9/4/2009 | OAK | Tomko | Signed | | | Before |
| 9/4/2009 | TOR | Hughes | Signed | | | Before |
| 9/4/2009 | TOR | Slaten | Released | | | Before |
| 9/7/2009 | BAL | Balester | Demoted to reserve roster | | | Before |
| 9/7/2009 | BAL | Hunter | Promoted to active roster | | | Before |
| 9/7/2009 | BAL | Smith | Demoted to reserve roster | | | Before |
| 9/7/2009 | CHA | Alfonzo | Released | | | Before |
| 9/7/2009 | OAK | Badenhop | Promoted to active roster | | | Before |
| 9/7/2009 | OAK | Myers | Promoted to active roster | | | Before |
| 9/7/2009 | OAK | Qualls | Demoted to reserve roster | | | Before |
| 9/7/2009 | SEA | Jones | Demoted to reserve roster | | | Before |
| 9/7/2009 | TEX | McLouth | Promoted to active roster | | | Before |
| 9/7/2009 | TEX | Nix | Demoted to reserve roster | | | Before |
| 9/11/2009 | DET | Nunez | Signed | | | Before |
| 9/11/2009 | DET | Thomas | Released | | | Before |
| 9/11/2009 | KC | Fiorentino | Signed | | | Before |
| 9/11/2009 | KC | Soriano | Demoted to reserve roster | | | Before |
| 9/11/2009 | KC | Soriano | Promoted to active roster | | | Before |
| 9/11/2009 | OAK | Tomko | Released | | | Before |
| 9/11/2009 | OAK | Uribe | Signed | | | Before |
| 9/11/2009 | TB | de la Cruz | Demoted to reserve roster | | | Before |
| 9/11/2009 | TB | Deduno | Signed | | | Before |
| 9/11/2009 | TB | Deduno | Promoted to active roster | | | Before |
| 9/11/2009 | TB | Richard | Demoted to reserve roster | | | Before |
| 9/11/2009 | TB | Simmons | Promoted to active roster | | | Before |
| 9/11/2009 | TOR | Hughes | Promoted to active roster | | | Before |
| 9/11/2009 | TOR | Wells | Promoted to active roster | | | Before |
| 9/14/2009 | BAL | Lowrie | Promoted to active roster | | | Before |
| 9/14/2009 | CHA | Armstrong | Released | | | Before |
| 9/14/2009 | CHA | Burton | Released | | | Before |
| 9/14/2009 | CHA | Diaz | Released | | | Before |
| 9/14/2009 | CHA | Hart | Promoted to active roster | | | Before |
| 9/14/2009 | CHA | Perez | Promoted to active roster | | | Before |
| 9/14/2009 | CHA | Thayer | Signed | | | Before |
| 9/14/2009 | CHA | Thayer | Promoted to active roster | | | Before |
| 9/14/2009 | CHA | Thomas | Signed | | | Before |
| 9/14/2009 | CHA | Thomas | Promoted to active roster | | | Before |
| 9/14/2009 | NYA | Gardner | Promoted to active roster | | | Before |
| 9/14/2009 | TB | Garcia | Promoted to active roster | | | Before |
| 9/14/2009 | TB | Robertson | Demoted to reserve roster | | | Before |
| 9/14/2009 | TEX | Condrey | Signed | | | Before |
| 9/14/2009 | TEX | Schoeneweis | Released | | | Before |
| 9/14/2009 | TOR | Pena | Demoted to reserve roster | | | Before |
| 9/15/2009 | KC | Soriano | Demoted to reserve roster | | | Before |
| 9/16/2009 | TEX | Byrnes | Promoted to active roster | | | Before |
| 9/18/2009 | ANA | McCarthy | Promoted to active roster | | | Before |
| 9/18/2009 | ANA | Morrison | Promoted to active roster | | | Before |
| 9/18/2009 | ANA | Saunders | Promoted to active roster | | | Before |
| 9/18/2009 | BAL | Hughes | Signed | | | Before |
| 9/18/2009 | MIN | Byrd | Released | | | Before |
| 9/18/2009 | MIN | Mahay | Signed | | | Before |
| 9/18/2009 | TB | Guzman | Demoted to reserve roster | | | Before |
| 9/18/2009 | TOR | Hughes | Released | | | Before |
| 9/21/2009 | CHA | Blevins | Released | | | Before |
| 9/21/2009 | CHA | Stults | Released | | | Before |
| 9/21/2009 | DET | Ascanio | Demoted to reserve roster | | | Before |
| 9/21/2009 | DET | Feldman | Promoted to active roster | | | Before |
| 9/21/2009 | DET | Mazzaro | Demoted to reserve roster | | | Before |
| 9/21/2009 | DET | Morton | Promoted to active roster | | | Before |
| 9/21/2009 | DET | Nunez | Promoted to active roster | | | Before |
| 9/21/2009 | DET | Rondon | Promoted to active roster | | | Before |
| 9/21/2009 | SEA | English | Promoted to active roster | | | Before |
| 9/21/2009 | SEA | Mickolio | Demoted to reserve roster | | | Before |
| 9/22/2009 | OAK | DiFelice | Demoted to reserve roster | | | Before |
| 9/25/2009 | DET | Schneider | Signed | | | Before |
| 9/28/2009 | CHA | Thayer | Released | | | Before |
| 9/28/2009 | DET | Martinez | Demoted to reserve roster | | | Before |
| 9/28/2009 | DET | Mijares | Promoted to active roster | | | Before |
| 9/28/2009 | DET | Norris | Promoted to active roster | | | Before |
| 9/28/2009 | DET | Oswalt | Demoted to reserve roster | | | Before |
| 9/28/2009 | DET | Rogers | Promoted to active roster | | | Before |
| 9/28/2009 | DET | Schneider | Released | | | Before |
| 9/28/2009 | DET | Shields | Demoted to reserve roster | | | Before |
| 9/28/2009 | MIN | Patterson | Released | | | Before |
| 9/28/2009 | NYA | Sabathia | Demoted to reserve roster | | | Before |
| 9/28/2009 | OAK | Myers | Demoted to reserve roster | | | Before |
| 9/28/2009 | TB | Brown | Demoted to reserve roster | | | Before |
| 9/28/2009 | TB | Garcia | Demoted to reserve roster | | | Before |
| 9/28/2009 | TB | Richard | Promoted to active roster | | | Before |
| 10/2/2009 | BAL | Hughes | Released | | | Before |
| 10/2/2009 | DET | Gallardo | Demoted to reserve roster | | | Before |
| 10/2/2009 | DET | Matos | Demoted to reserve roster | | | Before |
| 10/2/2009 | DET | Nathan | Demoted to reserve roster | | | Before |
| 10/2/2009 | DET | Romo | Demoted to reserve roster | | | Before |
| 10/2/2009 | DET | Sampson | Demoted to reserve roster | | | Before |
| 10/2/2009 | DET | Schneider | Signed | | | Before |
| 10/2/2009 | DET | Wieters | Demoted to reserve roster | | | Before |
| 10/2/2009 | NYA | Lehr | Signed | | | Before |
| 10/3/2009 | NYA | Lehr | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Feldman | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Gallardo | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Martinez | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Matos | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Mijares | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Morton | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Nathan | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Norris | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Nunez | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Oswalt | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Rogers | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Romo | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Rondon | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Sampson | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Schneider | Demoted to reserve roster | | | Before |
| 10/7/2009 | DET | Shields | Promoted to active roster | | | Before |
| 10/7/2009 | DET | Wieters | Promoted to active roster | | | Before |
| 10/7/2009 | NYA | Baker | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Baker | Promoted to active roster | | | Before |
| 10/7/2009 | NYA | Borbon | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Bruney | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Feliz | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Jones | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Lehr | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Melancon | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Rodriguez | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Rodriguez | Promoted to active roster | | | Before |
| 10/7/2009 | NYA | Rodriguez | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Ryan | Demoted to reserve roster | | | Before |
| 10/7/2009 | NYA | Ryan | Promoted to active roster | | | Before |
| 10/7/2009 | NYA | Sabathia | Promoted to active roster | | | Before |
| 10/7/2009 | NYA | Sheffield | Demoted to reserve roster | | | Before |
| 10/7/2009 | TOR | Branyan | Promoted to active roster | | | Before |
| 10/7/2009 | TOR | Fisher | Demoted to reserve roster | | | Before |
| 10/7/2009 | TOR | Shouse | Demoted to reserve roster | | | Before |
| 10/7/2009 | TOR | Snell | Demoted to reserve roster | | | Before |
| 10/7/2009 | TOR | Wells | Demoted to reserve roster | | | Before |
| 10/7/2009 | TOR | Zaun | Demoted to reserve roster | | | Before |
| 10/8/2009 | DET | Oswalt | Demoted to reserve roster | | | Before |
| 10/8/2009 | TEX | Rabelo | Demoted to reserve roster | | | Before |
| 10/15/2009 | DET | Feldman | Demoted to reserve roster | | | Before |
| 10/15/2009 | DET | Feldman | Promoted to active roster | | | Before |
| 10/15/2009 | DET | Gomez | Demoted to reserve roster | | | Before |
| 10/15/2009 | DET | Morton | Demoted to reserve roster | | | Before |
| 10/15/2009 | DET | Morton | Promoted to active roster | | | Before |
| 10/15/2009 | DET | Nunez | Demoted to reserve roster | | | Before |
| 10/15/2009 | DET | Nunez | Promoted to active roster | | | Before |
| 10/15/2009 | DET | Schneider | Demoted to reserve roster | | | Before |
| 10/15/2009 | DET | Schneider | Promoted to active roster | | | Before |
