Mariners Roster & Staff
Transactions
| Date | Transaction |
| 09/11/26 | Seattle Mariners sent CF Stuart Fairchild outright to Tacoma Rainiers. |
| 09/08/26 | Seattle Mariners activated RF Victor Robles. |
| 09/08/26 | Seattle Mariners designated CF Stuart Fairchild for assignment. |
| 09/08/26 | Seattle Mariners activated LHP Hoby Milner. |
| 09/08/26 | Seattle Mariners optioned RHP Troy Taylor to Tacoma Rainiers. |
| 09/06/26 | Seattle Mariners transferred RHP Nick Davila from the 15-day injured list to the 60-day injured list. SC joint sprain. |
| 09/06/26 | Seattle Mariners optioned 3B Patrick Wisdom to Tacoma Rainiers. |
| 09/06/26 | Seattle Mariners selected the contract of SS Michael Arroyo from Tacoma Rainiers. |
| 09/04/26 | Seattle Mariners recalled RHP Troy Taylor from Tacoma Rainiers. |
| 09/03/26 | RF Victor Robles roster status changed by Seattle Mariners. |
| 09/03/26 | Seattle Mariners placed CF Brennen Davis on the 60-day injured list. Left hamstring strain. |
| 09/03/26 | Seattle Mariners recalled CF Brennen Davis from Tacoma Rainiers. |
| 09/03/26 | Seattle Mariners sent RF Connor Joe outright to Tacoma Rainiers. |
| 09/03/26 | Seattle Mariners sent RHP Nolan Kingham outright to Tacoma Rainiers. |
| 09/03/26 | Seattle Mariners selected the contract of CF Stuart Fairchild from Tacoma Rainiers. |
| 09/02/26 | Seattle Mariners signed free agent RHP Simeon Woods Richardson to a minor league contract. |
| 09/01/26 | Seattle Mariners designated RF Connor Joe for assignment. |
| 09/01/26 | Seattle Mariners signed free agent LHP Hoby Milner. |
| 09/01/26 | Seattle Mariners designated RHP Nolan Kingham for assignment. |
| 09/01/26 | Seattle Mariners selected the contract of RF Lazaro Montes from Tacoma Rainiers. |