Trade Details
| ID | Item | From | Type | To | Drafted |
| 43947 | 2021 PHI Round 2 | Cardinals | TRADE | RedSox | Jo Adell |
| 43947 | 2021 STL Round 10 | Cardinals | TRADE | RedSox | |
| 43947 | 2021 STL Round 3 | Cardinals | TRADE | RedSox | Jose Barrero |
| 43947 | 2021 STL Round 4 | Cardinals | TRADE | RedSox | William Contreras |
| 43947 | 2021 STL Round 5 | Cardinals | TRADE | RedSox | Johan Oviedo |
| 43947 | 2021 STL Round 6 | Cardinals | TRADE | RedSox | Luis Torrens |
| 43947 | 2021 STL Round 7 | Cardinals | TRADE | RedSox | |
| 43947 | 2021 STL Round 8 | Cardinals | TRADE | RedSox | |
| 43947 | 2021 STL Round 9 | Cardinals | TRADE | RedSox | |
| 43947 | Framber Valdez | RedSox | TRADE | Cardinals | |
| 43947 | Matt Shoemaker | RedSox | TRADE | Cardinals | |
| 43947 | Yusmeiro Petit | RedSox | TRADE | Cardinals | |