| Transactions |
| Date | Team | Player | Type | OthTm | EffDate | When |
| 4/8/2004 | DCO | Baerga | Traded away | TRI | | After |
| 4/8/2004 | DCO | Bench | Traded away | TRI | | After |
| 4/8/2004 | DCO | Biggio | Acquired via trade | TRI | | After |
| 4/8/2004 | DCO | Jones,A | Acquired via trade | TRI | | After |
| 4/9/2004 | DCO | Davis | Signed | | | Before |
| 4/9/2004 | DCO | Greenwell | Released | | | Before |
| 4/13/2004 | DCO | Barker | Released | | | Before |
| 4/13/2004 | DCO | Barker | Signed | | | Before |
| 4/13/2004 | DCO | Barker | Signed | | | Before |
| 4/13/2004 | DCO | Niekro | Released | | | Before |
| 4/13/2004 | DCO | Niekro | Released | | | Before |
| 4/13/2004 | DCO | Niekro | Signed | | | Before |
| 4/13/2004 | DCO | Niekro | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Averill | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Banks | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Blyleven | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Dawson | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Dickey | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Evans | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Garcia | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Halter | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Horner | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | McCarver | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Murphy | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Newcombe | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Randolph | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Sanford | Demoted to reserve roster | | | Before |
| 5/19/2004 | RED | Sax,S | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Scurry | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Spohrer | Promoted to active roster | | | Before |
| 5/19/2004 | RED | Wilson | Demoted to reserve roster | | | Before |
| 5/19/2004 | WIN | Hall | Promoted to active roster | | | Before |
| 5/19/2004 | WIN | McMichael | Demoted to reserve roster | | | Before |
| 5/19/2004 | WIN | O'Dell | Promoted to active roster | | | Before |
| 5/19/2004 | WIN | Pierce | Promoted to active roster | | | Before |
| 5/19/2004 | WIN | Scott | Demoted to reserve roster | | | Before |
| 5/19/2004 | WIN | Williamson | Demoted to reserve roster | | | Before |
