| Transactions |
| Date | Team | Player | Type | OthTm | EffDate | When |
| 4/12/1931 | SP | Dickey | Demoted to reserve roster | | | Before |
| 4/12/1931 | SP | Grace | Promoted to active roster | | | Before |
| 4/17/1931 | SP | Bolton | Demoted to reserve roster | | | Before |
| 4/17/1931 | SP | Dickey | Promoted to active roster | | | Before |
| 4/17/1931 | SP | Johnson | Promoted to active roster | | | Before |
| 4/17/1931 | SP | Schumacher | Demoted to reserve roster | | | Before |
| 4/27/1931 | CCT | Bennett | Demoted to reserve roster | | | Before |
| 4/27/1931 | CCT | Charleston | Promoted to active roster | | | Before |
| 4/27/1931 | CCT | Flowers | Demoted to reserve roster | | | Before |
| 4/27/1931 | CCT | Groskloss | Demoted to reserve roster | | | Before |
| 4/27/1931 | CCT | Lundy | Promoted to active roster | | | Before |
| 4/27/1931 | CCT | McCurdy | Promoted to active roster | | | Before |
| 4/27/1931 | KM | Bengough | Demoted to reserve roster | | | Before |
| 4/27/1931 | KM | Myatt | Promoted to active roster | | | Before |
| 4/27/1931 | SP | Bolton | Promoted to active roster | | | Before |
| 4/27/1931 | SP | Grace | Demoted to reserve roster | | | Before |
| 5/2/1931 | CCT | Flowers | Promoted to active roster | | | Before |
| 5/2/1931 | CCT | McCurdy | Demoted to reserve roster | | | Before |
| 5/2/1931 | SP | Bolton | Demoted to reserve roster | | | Before |
| 5/2/1931 | SP | Grace | Promoted to active roster | | | Before |
| 5/12/1931 | CCT | Flowers | Demoted to reserve roster | | | Before |
| 5/12/1931 | CCT | McCurdy | Promoted to active roster | | | Before |
| 5/12/1931 | QC | Herman | Demoted to reserve roster | | | Before |
| 5/12/1931 | QC | Reese | Promoted to active roster | | | Before |
| 5/17/1931 | GHG | Moore | Promoted to active roster | | | Before |
| 5/17/1931 | GHG | Walker | Demoted to reserve roster | | | Before |
| 5/21/1931 | KM | Adams | Traded away | MN | | After |
| 5/21/1931 | KM | Fothergill | Traded away | MN | | After |
| 5/21/1931 | KM | Vergez | Acquired via trade | MN | | After |
| 5/21/1931 | KM | White, C | Acquired via trade | MN | | After |
| 5/21/1931 | MN | Adams | Acquired via trade | KM | | After |
| 5/21/1931 | MN | Fothergill | Acquired via trade | KM | | After |
| 5/21/1931 | MN | Vergez | Traded away | KM | | After |
| 5/21/1931 | MN | White, C | Traded away | KM | | After |
| 5/27/1931 | BT | Finney | Demoted to reserve roster | | | Before |
| 5/27/1931 | BT | Hildebrand | Demoted to reserve roster | | | Before |
| 5/27/1931 | FV | Andrews | Demoted to reserve roster | | | Before |