| Transactions | ||||||
| Date | Team | Player | Type | OthTm | EffDate | When |
| 4/2/2009 | LON | Aardsma | Acquired via trade | EDG | After | |
| 4/2/2009 | LON | Marshall,S | Traded away | EDG | After | |
| 4/16/2009 | MAD | Kendall | Signed | Before | ||
| 4/16/2009 | ROK | Liriano | Demoted to reserve roster | Before | ||
| 4/16/2009 | ROK | Palmer | Demoted to reserve roster | Before | ||
| 4/16/2009 | ROK | Palmer | Promoted to active roster | Before | ||
| 4/16/2009 | ROK | Pie | Signed | Before | ||
| 6/17/2009 | LON | Morton | Traded away | WIZ | After | |
| 6/17/2009 | LON | Nathan | Acquired via trade | WIZ | After | |
| 6/18/2009 | LON | Condrey | Demoted to reserve roster | Before | ||
| 7/9/2009 | Pal | Crisp | Promoted to active roster | Before | ||
| 7/9/2009 | Pal | Wilson,Ja | Demoted to reserve roster | Before | ||
| 7/22/2009 | Pal | Hairston,S | Acquired via trade | WIZ | After | |
| 7/22/2009 | Pal | Kuroda | Acquired via trade | WIZ | After | |
| 7/22/2009 | Pal | Saltalamacchia | Traded away | WIZ | After | |
| 7/22/2009 | Pal | Stauffer | Traded away | WIZ | After | |
| 7/23/2009 | Pal | Crisp | Demoted to reserve roster | Before | ||