League transaction log -- American
Regular season
| Transactions |
| Date | Team | Player | Type | OthTm | EffDate | When |
| 3/31/2021 | CCC | Mayers | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | aaaArihara | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | aaaStott | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | Astudillo | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | Chapman,A | Traded away | LAH | | After |
| 3/31/2021 | COL | Chavis | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | Dubon | Traded away | LAH | | After |
| 3/31/2021 | COL | Mountcastle | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | Perez,O | Traded away | LAH | | After |
| 3/31/2021 | COL | Sanchez,G | Acquired via trade | LAH | | After |
| 3/31/2021 | COL | Taylor,C | Traded away | LAH | | After |
| 3/31/2021 | COL | Vazquez | Traded away | LAH | | After |
| 3/31/2021 | ISO | aaaLuciano | Traded away | SCA | | After |
| 3/31/2021 | ISO | Darvish | Acquired via trade | SCA | | After |
| 3/31/2021 | ISO | Garcia,LH | Traded away | LVB | | After |
| 3/31/2021 | ISO | Kim | Acquired via trade | LVB | | After |
| 3/31/2021 | ISO | Rogers,Tr | Traded away | LVB | | After |
| 3/31/2021 | ISO | Wacha | Traded away | SCA | | After |
| 3/31/2021 | JER | Candelario | Acquired via trade | LVB | | After |
| 3/31/2021 | JER | Pujols | Traded away | LVB | | After |
| 3/31/2021 | JER | Rodgers | Traded away | LVB | | After |
| 3/31/2021 | LAH | aaaArihara | Traded away | COL | | After |
| 3/31/2021 | LAH | aaaStott | Traded away | COL | | After |
| 3/31/2021 | LAH | aaaWittJr | Traded away | LVB | | After |
| 3/31/2021 | LAH | Astudillo | Traded away | COL | | After |
| 3/31/2021 | LAH | Chapman,A | Acquired via trade | COL | | After |
| 3/31/2021 | LAH | Chavis | Traded away | COL | | After |
| 3/31/2021 | LAH | Dubon | Acquired via trade | COL | | After |
| 3/31/2021 | LAH | Mayers | Traded away | CCC | | After |
| 3/31/2021 | LAH | Mountcastle | Traded away | COL | | After |
| 3/31/2021 | LAH | Nimmo | Acquired via trade | LVB | | After |
| 3/31/2021 | LAH | Perez,O | Acquired via trade | COL | | After |
| 3/31/2021 | LAH | Sanchez,G | Traded away | COL | | After |
| 3/31/2021 | LAH | Taylor,C | Acquired via trade | COL | | After |
| 3/31/2021 | LAH | Vazquez | Acquired via trade | COL | | After |
| 3/31/2021 | LVB | aaaColas | Traded away | BOM | | After |
| 3/31/2021 | LVB | aaaFaedo | Traded away | BOM | | After |
| 3/31/2021 | LVB | aaaWittJr | Acquired via trade | LAH | | After |
| 3/31/2021 | LVB | Candelario | Traded away | JER | | After |
| 3/31/2021 | LVB | Cease | Acquired via trade | BOM | | After |
| 3/31/2021 | LVB | Diaz,I | Acquired via trade | NHH | | After |
| 3/31/2021 | LVB | Dickerson,A | Traded away | BOM | | After |
| 3/31/2021 | LVB | Garcia,LH | Acquired via trade | ISO | | After |
| 3/31/2021 | LVB | Huff | Acquired via trade | BOM | | After |
| 3/31/2021 | LVB | Kieboom | Acquired via trade | BOM | | After |
| 3/31/2021 | LVB | Kim | Traded away | ISO | | After |
| 3/31/2021 | LVB | Luplow | Acquired via trade | BOM | | After |
| 3/31/2021 | LVB | Nimmo | Traded away | LAH | | After |
| 3/31/2021 | LVB | Pujols | Acquired via trade | JER | | After |
| 3/31/2021 | LVB | Reyes,V | Traded away | NHH | | After |
| 3/31/2021 | LVB | Rodgers | Acquired via trade | JER | | After |
| 3/31/2021 | LVB | Rogers,Tr | Acquired via trade | ISO | | After |
| 3/31/2021 | LVB | Schoop | Traded away | BOM | | After |
| 3/31/2021 | LVB | Stallings | Traded away | BOM | | After |
| 3/31/2021 | LVB | Suarez,E | Acquired via trade | NHH | | After |
| 3/31/2021 | LVB | Urshela | Traded away | NHH | | After |
| 3/31/2021 | LVB | Wendelken | Traded away | BOM | | After |
| 3/31/2021 | SCA | aaaLuciano | Acquired via trade | ISO | | After |
| 3/31/2021 | SCA | Darvish | Traded away | ISO | | After |
| 3/31/2021 | SCA | Wacha | Acquired via trade | ISO | | After |