| Transactions |
| Date | Team | Player | Type | OthTm | EffDate | When |
| 3/2/2009 | FH | Wade | Acquired via trade | MSB | | After |
| 3/2/2009 | MSB | Wade | Traded away | FH | | After |
| 3/3/2009 | MSB | Batista | Demoted to reserve roster | | | Before |
| 3/3/2009 | MSB | Bourn | Demoted to reserve roster | | | Before |
| 3/3/2009 | MSB | Buchholz,C | Demoted to reserve roster | | | Before |
| 3/3/2009 | MSB | Garland | Demoted to reserve roster | | | Before |
| 3/3/2009 | MSB | Hammel | Demoted to reserve roster | | | Before |
| 3/3/2009 | MSB | Hernandez,Li | Demoted to reserve roster | | | Before |
| 3/3/2009 | MSB | Silva | Demoted to reserve roster | | | Before |
| 3/7/2009 | SS | Betancourt,Y | Promoted to active roster | | | Before |
| 3/18/2009 | BB | Duchscherer | Demoted to reserve roster | | | Before |
| 3/19/2009 | BoB | Bannister | Demoted to reserve roster | | | Before |
| 3/19/2009 | BoB | Bonser | Demoted to reserve roster | | | Before |
| 3/19/2009 | BoB | Millwood | Demoted to reserve roster | | | Before |
| 3/20/2009 | ACS | Buchholz,T | Acquired via trade | SC | | After |
| 3/20/2009 | ACS | Bush | Acquired via trade | SCR | | After |
| 3/20/2009 | ACS | Cust | Traded away | SCR | | After |
| 3/20/2009 | ACS | Gallagher | Traded away | SC | | After |
| 3/20/2009 | ACS | Hanson | Traded away | SC | | After |
| 3/20/2009 | ACS | Jones,An | Traded away | SC | | After |
| 3/20/2009 | ACS | Lackey | Acquired via trade | SC | | After |
| 3/20/2009 | ACS | Ludwick | Acquired via trade | SCR | | After |
| 3/20/2009 | ACS | Morneau | Acquired via trade | SC | | After |
| 3/20/2009 | ACS | Wieters | Traded away | SCR | | After |
| 3/20/2009 | DH | Dumatrait | Promoted to active roster | | | Before |
| 3/20/2009 | SC | Buchholz,T | Traded away | ACS | | After |
| 3/20/2009 | SC | Gallagher | Acquired via trade | ACS | | After |
| 3/20/2009 | SC | Hanson | Acquired via trade | ACS | | After |
| 3/20/2009 | SC | Jones,An | Acquired via trade | ACS | | After |
| 3/20/2009 | SC | Lackey | Traded away | ACS | | After |
| 3/20/2009 | SC | Morneau | Traded away | ACS | | After |
| 3/20/2009 | SCR | Bush | Traded away | ACS | | After |
| 3/20/2009 | SCR | Cust | Acquired via trade | ACS | | After |
| 3/20/2009 | SCR | Ludwick | Traded away | ACS | | After |
| 3/20/2009 | SCR | Wieters | Acquired via trade | ACS | | After |
| 3/21/2009 | SCR | Pena,TR | Promoted to active roster | | | Before |
| 3/24/2009 | BMD | Fogg | Demoted to reserve roster | | | Before |
| 3/24/2009 | BMD | Gload | Demoted to reserve roster | | | Before |
| 3/24/2009 | BMD | Ponson | Demoted to reserve roster | | | Before |
| 3/24/2009 | BMD | Rogers | Demoted to reserve roster | | | Before |
| 3/24/2009 | BMD | Shouse | Demoted to reserve roster | | | Before |
| 3/24/2009 | BMD | Suppan | Demoted to reserve roster | | | Before |
| 3/26/2009 | DMB | Cabrera,D | Demoted to reserve roster | | | Before |
| 3/26/2009 | DMB | Cabrera,D | Promoted to active roster | | | Before |
| 3/26/2009 | DMB | Gabbard | Demoted to reserve roster | | | Before |
| 3/26/2009 | DMB | Harang | Demoted to reserve roster | | | Before |
| 3/26/2009 | DMB | Pinto | Demoted to reserve roster | | | Before |
| 3/26/2009 | DMB | Rauch | Promoted to active roster | | | Before |
| 3/26/2009 | DMB | Reynolds,G | Demoted to reserve roster | | | Before |
| 3/27/2009 | DMB | Cabrera,D | Demoted to reserve roster | | | Before |
| 3/27/2009 | SS | Betancourt,Y | Demoted to reserve roster | | | Before |
| 3/27/2009 | SS | Grilli | Demoted to reserve roster | | | Before |
| 3/28/2009 | JJ | Walker,T | Demoted to reserve roster | | | Before |
| 3/31/2009 | BB | Bay | Acquired via trade | MSB | | After |
| 3/31/2009 | BB | Snider | Traded away | MSB | | After |
| 3/31/2009 | MSB | Bay | Traded away | BB | | After |
| 3/31/2009 | MSB | Snider | Acquired via trade | BB | | After |
| 4/1/2009 | HH | Dotel | Acquired via trade | SS | | After |
| 4/1/2009 | HH | Feliz | Traded away | SS | | After |
| 4/1/2009 | HH | Grilli | Acquired via trade | SS | | After |
| 4/1/2009 | HH | Gross | Traded away | SS | | After |
| 4/1/2009 | SS | Dotel | Traded away | HH | | After |
| 4/1/2009 | SS | Feliz | Acquired via trade | HH | | After |
| 4/1/2009 | SS | Grilli | Traded away | HH | | After |
| 4/1/2009 | SS | Gross | Acquired via trade | HH | | After |
| 4/4/2009 | BB | Duchscherer | Promoted to active roster | | | Before |
| 4/4/2009 | BB | Francis | Demoted to reserve roster | | | Before |
| 4/4/2009 | BB | Matsui,H | Demoted to reserve roster | | | Before |
| 4/6/2009 | SCR | Villanueva | Promoted to active roster | | | Before |
| 4/8/2009 | HH | Dotel | Traded away | LAC | | After |
| 4/8/2009 | HH | Grilli | Traded away | LAC | | After |
| 4/8/2009 | HH | Kubel | Acquired via trade | LAC | | After |
| 4/8/2009 | HH | Rolen | Acquired via trade | LAC | | After |
| 4/8/2009 | LAC | Dotel | Acquired via trade | HH | | After |
| 4/8/2009 | LAC | Grilli | Acquired via trade | HH | | After |
| 4/8/2009 | LAC | Kubel | Traded away | HH | | After |
| 4/8/2009 | LAC | Rolen | Traded away | HH | | After |