Mariners Roster & Staff
Transactions
| Date | Transaction |
| 01/30/26 | Seattle Mariners invited non-roster OF Jonny Farmelo to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Teddy McGraw to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Michael Morales to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster SS Michael Arroyo to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster C Nick Raposo to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster LHP Austin Kitchen to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Charlie Beilenson to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Nick Davila to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster C Josh Caron to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster CF Victor Labrada to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Tyler Cleveland to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster OF Blake Rambusch to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster C Luke Stevenson to spring training. |
| 01/30/26 | Seattle Mariners signed free agent C Brian O'Keefe to a minor league contract and invited him to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster LHP Kade Anderson to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster OF Spencer Packard to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster C Connor Charping to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster SS Colt Emerson to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster OF Jared Sundstrom to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster SHP Jurrangelo Cijntje to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Ryan Sloan to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster RF Lazaro Montes to spring training. |
| 01/30/26 | RHP Nick Davila roster status changed by Seattle Mariners. |
| 01/30/26 | Seattle Mariners invited non-roster RHP Guillo Zuñiga to spring training. |
| 01/30/26 | Seattle Mariners invited non-roster 2B Brock Rodden to spring training. |
| 01/28/26 | Seattle Mariners sent LHP Jhonathan Díaz outright to Tacoma Rainiers. |
| 01/27/26 | Seattle Mariners designated RHP Jackson Kowar for assignment. |
| 01/27/26 | Seattle Mariners signed free agent RHP Gunner Mayer to a minor league contract. |
| 01/27/26 | Minnesota Twins traded C Jhonny Pereda to Seattle Mariners for cash. |
| 01/26/26 | Seattle Mariners signed free agent 3B Will Wilson to a minor league contract. |
| 01/26/26 | Seattle Mariners signed free agent C Aaron McKeithan to a minor league contract. |
| 01/26/26 | 3B Will Wilson roster status changed by Seattle Mariners. |
| 01/26/26 | Seattle Mariners signed free agent RHP Abdiel Mendoza to a minor league contract. |
| 01/24/26 | Seattle Mariners signed free agent C Jakson Reetz to a minor league contract. |
| 01/24/26 | C Jakson Reetz roster status changed by Seattle Mariners. |
| 01/23/26 | Seattle Mariners designated LHP Jhonathan Díaz for assignment. |
| 01/23/26 | New York Mets traded RHP Cooper Criswell to Seattle Mariners for cash. |
| 01/22/26 | RHP Dane Dunning roster status changed by Seattle Mariners. |
| 01/22/26 | Seattle Mariners signed free agent RHP Dane Dunning to a minor league contract. |
| 01/22/26 | Seattle Mariners sent 2B Samad Taylor outright to Tacoma Rainiers. |
| 01/21/26 | Seattle Mariners signed free agent LHP Jack Bowery to a minor league contract. |
| 01/20/26 | Seattle Mariners signed free agent 1B Patrick Wisdom to a minor league contract. |
| 01/20/26 | 1B Patrick Wisdom roster status changed by Seattle Mariners. |
| 01/16/26 | Seattle Mariners signed free agent RHP Gabe Mosser to a minor league contract. |
| 01/16/26 | RHP Gabe Mosser roster status changed by Seattle Mariners. |
| 01/15/26 | Seattle Mariners designated 2B Samad Taylor for assignment. |
| 01/15/26 | Seattle Mariners signed free agent SS Leonardo Reynoso to a minor league contract. |
| 01/15/26 | Seattle Mariners signed free agent OF Juan Rijo to a minor league contract. |
| 01/15/26 | Seattle Mariners signed free agent OF Gregory Pio to a minor league contract. |
| 01/15/26 | Seattle Mariners signed free agent OF Jarvis Gomez to a minor league contract. |
| 01/15/26 | Seattle Mariners signed free agent OF Ambeiro Recio to a minor league contract. |
| 01/15/26 | Cincinnati Reds traded RHP Yosver Zulueta to Seattle Mariners for RHP Dusty Revis. |
| 01/15/26 | Cincinnati Reds traded RHP Yosver Zulueta to Seattle Mariners for RHP Dusty Revis. |
| 01/12/26 | 2B J.T. Arruda roster status changed by Seattle Mariners. |
| 01/12/26 | Seattle Mariners signed free agent SS J.T. Arruda to a minor league contract. |
| 01/08/26 | Seattle Mariners signed free agent RHP Michael Rucker to a minor league contract. |
| 01/08/26 | RHP Michael Rucker roster status changed by Seattle Mariners. |
| 01/04/26 | RHP Logan Evans changed number to 23. |