| Transactions | ||||||
| Date | Team | Player | Type | OthTm | EffDate | When |
| 3/11/1988 | COP | Brett | Acquired via trade | CRH |   | After |
| 3/11/1988 | COP | Buhner | Traded away | CRH |   | After |
| 3/11/1988 | CRH | Brett | Traded away | COP |   | After |
| 3/11/1988 | CRH | Buhner | Acquired via trade | COP |   | After |
| 4/15/1988 | Pal | Quinones | Signed |   |   | Before |
| 4/15/1988 | Pal | Trout | Released |   |   | Before |
| 5/29/1988 | GEO | McLemore | Traded away | ROK |   | After |
| 5/29/1988 | GEO | Morgan | Traded away | ROK |   | After |
| 5/29/1988 | GEO | Ojeda | Acquired via trade | ROK |   | After |
| 5/29/1988 | ROK | McLemore | Acquired via trade | GEO |   | After |
| 5/29/1988 | ROK | Morgan | Acquired via trade | GEO |   | After |
| 5/29/1988 | ROK | Ojeda | Traded away | GEO |   | After |
| 6/3/1988 | GEO | Dawson | Acquired via trade | KDB |   | After |
| 6/3/1988 | GEO | Sierra | Traded away | KDB |   | After |
| 6/3/1988 | KDB | Dawson | Traded away | GEO |   | After |
| 6/3/1988 | KDB | Sierra | Acquired via trade | GEO |   | After |
| 6/28/1988 | CCL | Armstrong | Acquired via trade | LON |   | After |
| 6/28/1988 | CCL | Duncan | Acquired via trade | LON |   | After |
| 6/28/1988 | CCL | Speier | Traded away | LON |   | After |
| 6/28/1988 | CCL | Washington | Traded away | LON |   | After |
| 6/28/1988 | LON | Armstrong | Traded away | CCL |   | After |
| 6/28/1988 | LON | Duncan | Traded away | CCL |   | After |
| 6/28/1988 | LON | Speier | Acquired via trade | CCL |   | After |
| 6/28/1988 | LON | Washington | Acquired via trade | CCL |   | After |
| 6/29/1988 | CCL | Maldonado | Promoted to active roster |   |   | Before |
| 6/29/1988 | LON | Speier | Demoted to reserve roster |   |   | Before |
| 10/13/1988 | COL | Candelaria | Demoted to reserve roster |   |   | Before |
| 10/13/1988 | COP | Perez | Demoted to reserve roster |   |   | Before |
| 1/1/2024 | CCL | Freeman | Acquired via trade | EDG |   | After |
| 1/1/2024 | CCL | Gallego | Traded away | EDG |   | After |
| 1/1/2024 | EDG | Freeman | Traded away | CCL |   | After |
| 1/1/2024 | EDG | Gallego | Acquired via trade | CCL |   | After |