Athletics Roster & Staff
Transactions
| Date | Transaction |
| 02/28/21 | 3B Edwin Diaz assigned to Oakland Athletics . |
| 02/28/21 | SS Logan Davidson assigned to Oakland Athletics . |
| 02/28/21 | P Bryce Conley assigned to Oakland Athletics . |
| 02/28/21 | CF Cody Thomas assigned to Oakland Athletics . |
| 02/28/21 | P Jeff Criswell assigned to Oakland Athletics . |
| 02/28/21 | P Zach Jackson assigned to Oakland Athletics . |
| 02/28/21 | CF Cody Thomas assigned to Oakland Athletics . |
| 02/28/21 | P Bryce Conley assigned to Oakland Athletics . |
| 02/28/21 | P Jeff Criswell assigned to Oakland Athletics . |
| 02/28/21 | P Zach Jackson assigned to Oakland Athletics . |
| 02/28/21 | 3B Edwin Diaz assigned to Oakland Athletics . |
| 02/28/21 | SS Logan Davidson assigned to Oakland Athletics . |
| 02/27/21 | Oakland Athletics sent P Paul Blackburn outright to Las Vegas Aviators. |
| 02/24/21 | Oakland Athletics traded CF Dustin Fowler to Pittsburgh Pirates for cash. |
| 02/23/21 | Chad Pinder changed number to 4. |
| 02/23/21 | Oakland Athletics signed free agent 1B Mitch Moreland. |
| 02/23/21 | Oakland Athletics signed free agent 1B Mitch Moreland. |
| 02/23/21 | Oakland Athletics signed free agent 1B Mitch Moreland. |
| 02/23/21 | Oakland Athletics designated RHP Paul Blackburn for assignment. |
| 02/22/21 | Oakland Athletics signed free agent RHP Trevor Rosenthal. |
| 02/22/21 | Oakland Athletics designated CF Dustin Fowler for assignment. |
| 02/19/21 | Nik Turley changed number to 23. |
| 02/19/21 | Oakland Athletics signed free agent P Yusmeiro Petit. |
| 02/19/21 | Oakland Athletics signed free agent RHP Yusmeiro Petit. |
| 02/19/21 | Oakland Athletics signed free agent P Yusmeiro Petit. |
| 02/18/21 | Oakland Athletics signed free agent P Sergio Romo. |
| 02/18/21 | Brian Schlitter changed number to 99. |
| 02/18/21 | Oakland Athletics signed free agent P Sergio Romo. |
| 02/18/21 | Oakland Athletics signed free agent RHP Sergio Romo. |
| 02/18/21 | Oakland Athletics placed RHP Frankie Montas on the 10-day injured list. |
| 02/18/21 | P Brian Schlitter changed number to 99. |
| 02/17/21 | 1B Frank Schwindel changed number to 78. |
| 02/17/21 | Frank Schwindel changed number to 78. |
| 02/16/21 | 2B Nate Orf retired. |
| 02/16/21 | Oakland Athletics signed free agent RHP Mike Fiers. |
| 02/15/21 | Oakland Athletics signed free agent LHP Aaron Brown to a minor league contract. |
| 02/12/21 | Los Angeles Dodgers traded LHP Adam Kolarek and RF Cody Thomas to Oakland Athletics for 3B Sheldon Neuse and RHP Gus Varland. |
| 02/12/21 | Los Angeles Dodgers traded LHP Adam Kolarek and RF Cody Thomas to Oakland Athletics for 3B Sheldon Neuse and RHP Gus Varland. |
| 02/12/21 | Los Angeles Dodgers traded LHP Adam Kolarek and RF Cody Thomas to Oakland Athletics for 3B Sheldon Neuse and RHP Gus Varland. |
| 02/12/21 | Los Angeles Dodgers traded LHP Adam Kolarek and RF Cody Thomas to Oakland Athletics for 3B Sheldon Neuse and RHP Gus Varland. |
| 02/10/21 | Oakland Athletics signed free agent SS Jed Lowrie to a minor league contract and invited him to spring training. |
| 02/10/21 | Oakland Athletics signed free agent SS Jed Lowrie. |
| 02/06/21 | Oakland Athletics traded LF Khris Davis, C Jonah Heim and RHP Dane Acker to Texas Rangers for SS Elvis Andrus, C Aramis Garcia and cash. |
| 02/06/21 | Oakland Athletics traded LF Khris Davis, C Jonah Heim and RHP Dane Acker to Texas Rangers for SS Elvis Andrus, C Aramis Garcia and cash. |
| 02/06/21 | Oakland Athletics traded LF Khris Davis, C Jonah Heim and RHP Dane Acker to Texas Rangers for SS Elvis Andrus, C Aramis Garcia and cash. |
| 02/06/21 | Oakland Athletics traded LF Khris Davis, C Jonah Heim and RHP Dane Acker to Texas Rangers for SS Elvis Andrus, C Aramis Garcia and cash. |
| 02/06/21 | Oakland Athletics traded LF Khris Davis, C Jonah Heim and RHP Dane Acker to Texas Rangers for SS Elvis Andrus, C Aramis Garcia and cash. |
| 02/02/21 | Oakland Athletics signed free agent C Carlos Perez to a minor league contract and invited him to spring training. |
| 02/02/21 | Oakland Athletics signed free agent RHP Deolis Guerra to a minor league contract and invited him to spring training. |
| 02/02/21 | Oakland Athletics invited non-roster C Kyle McCann to spring training. |
| 02/02/21 | Oakland Athletics invited non-roster C Kyle McCann to spring training. |
| 02/02/21 | Oakland Athletics signed free agent C Carlos Perez. |