| Transactions | ||||||
| Date | Team | Player | Type | OthTm | EffDate | When |
| 3/11/2008 | CRH | Cantu | Acquired via trade | MID | After | |
| 3/11/2008 | CRH | Mientkiewicz | Traded away | MID | After | |
| 3/11/2008 | MID | Cantu | Traded away | CRH | After | |
| 3/11/2008 | MID | Mientkiewicz | Acquired via trade | CRH | After | |
| 4/2/2008 | BT | Loney | Traded away | MAD | After | |
| 4/2/2008 | BT | Pierre | Acquired via trade | MAD | After | |
| 4/2/2008 | MAD | Beltre | Traded away | TON | After | |
| 4/2/2008 | MAD | Burrell | Acquired via trade | TON | After | |
| 4/2/2008 | MAD | Drew,S | Acquired via trade | TON | After | |
| 4/2/2008 | MAD | Hardy | Traded away | TON | After | |
| 4/2/2008 | MAD | Loney | Acquired via trade | BT | After | |
| 4/2/2008 | MAD | Pierre | Traded away | BT | After | |
| 4/2/2008 | MAD | Ramirez,Ar | Acquired via trade | TON | After | |
| 4/2/2008 | TON | Beltre | Acquired via trade | MAD | After | |
| 4/2/2008 | TON | Burrell | Traded away | MAD | After | |
| 4/2/2008 | TON | Drew,S | Traded away | MAD | After | |
| 4/2/2008 | TON | Hardy | Acquired via trade | MAD | After | |
| 4/2/2008 | TON | Ramirez,Ar | Traded away | MAD | After | |
| 4/17/2008 | BON | Gonzalez,C | Demoted to reserve roster | Before | ||
| 4/17/2008 | BON | Neshek | Demoted to reserve roster | Before | ||
| 4/17/2008 | BON | Perkins | Demoted to reserve roster | Before | ||
| 4/17/2008 | BON | Tejada,M | Demoted to reserve roster | Before | ||
| 4/17/2008 | EDG | Hammel | Demoted to reserve roster | Before | ||
| 4/24/2008 | MUL | Wilson,Br | Demoted to reserve roster | Before | ||
| 4/30/2008 | COP | Ankiel | Acquired via trade | WIZ | After | |
| 4/30/2008 | COP | Davis,R | Traded away | WIZ | After | |
| 4/30/2008 | WIZ | Ankiel | Traded away | COP | After | |
| 4/30/2008 | WIZ | Davis,R | Acquired via trade | COP | After | |
| 5/1/2008 | WIZ | Davis,R | Promoted to active roster | Before | ||
| 5/7/2008 | BT | Aardsma | Traded away | EDG | After | |
| 5/7/2008 | BT | Chamberlain | Acquired via trade | EDG | After | |
| 5/7/2008 | BT | McClung | Traded away | EDG | After | |
| 5/7/2008 | EDG | Aardsma | Acquired via trade | BT | After | |
| 5/7/2008 | EDG | Chamberlain | Traded away | BT | After | |
| 5/7/2008 | EDG | McClung | Acquired via trade | BT | After | |
| 5/14/2008 | CCL | Rollins | Traded away | MID | After | |
| 5/14/2008 | CCL | Young,M | Acquired via trade | MID | After | |
| 5/14/2008 | MID | Rollins | Acquired via trade | CCL | After | |
| 5/14/2008 | MID | Young,M | Traded away | CCL | After | |
| 5/15/2008 | Pal | Jacobs | Promoted to active roster | Before | ||
| 5/22/2008 | COP | Church | Demoted to reserve roster | Before | ||
| 6/4/2008 | BT | Devine | Acquired via trade | ROK | After | |
| 6/4/2008 | BT | Wuertz | Traded away | ROK | After | |
| 6/4/2008 | ROK | Devine | Traded away | BT | After | |
| 6/4/2008 | ROK | Wuertz | Acquired via trade | BT | After | |
| 7/9/2026 | BON | Bay | Acquired via trade | Pal | After | |
| 7/9/2026 | BON | Swisher | Traded away | Pal | After | |
| 7/9/2026 | CRH | Carpenter,C | Traded away | TON | After | |
| 7/9/2026 | CRH | Sheets | Acquired via trade | TON | After | |
| 7/9/2026 | Pal | Bay | Traded away | BON | After | |
| 7/9/2026 | Pal | Swisher | Acquired via trade | BON | After | |
| 7/9/2026 | TON | Carpenter,C | Acquired via trade | CRH | After | |
| 7/9/2026 | TON | Sheets | Traded away | CRH | After | |