Mariners Roster & Staff
Transactions
| Date | Transaction |
| 03/15/26 | OF Konni Durschlag assigned to Seattle Mariners. |
| 03/14/26 | RHP Wyatt Lunsford-Shenkman assigned to Seattle Mariners. |
| 03/14/26 | OF Ryan Picollo assigned to Seattle Mariners. |
| 03/14/26 | Seattle Mariners optioned LHP Robinson Ortiz to Tacoma Rainiers. |
| 03/13/26 | OF Anthony Donofrio assigned to Seattle Mariners. |
| 03/13/26 | LHP Jacob Denner assigned to Seattle Mariners. |
| 03/13/26 | Seattle Mariners optioned RHP Troy Taylor to Tacoma Rainiers. |
| 03/13/26 | Seattle Mariners optioned LHP Josh Simpson to Tacoma Rainiers. |
| 03/12/26 | OF Aiden Taurek assigned to Seattle Mariners. |
| 03/11/26 | CF Curtis Washington Jr. assigned to Seattle Mariners. |
| 03/11/26 | Seattle Mariners optioned RHP Blas Castaño to Tacoma Rainiers. |
| 03/11/26 | Seattle Mariners optioned RHP Domingo Gonzalez to Tacoma Rainiers. |
| 03/10/26 | SS Carter Dorighi assigned to Seattle Mariners. |
| 03/08/26 | Seattle Mariners optioned RHP Ryan Loutos to Tacoma Rainiers. |
| 03/07/26 | C Grant Jay assigned to Seattle Mariners. |
| 03/07/26 | 2B Josh Hood assigned to Seattle Mariners. |
| 03/07/26 | 2B Alejo Lopez assigned to Seattle Mariners. |
| 03/06/26 | C Matthew Ellis assigned to Seattle Mariners. |
| 03/06/26 | OF Korbyn Dickerson assigned to Seattle Mariners. |
| 03/05/26 | LF Colin Davis assigned to Seattle Mariners. |
| 03/05/26 | C Aaron McKeithan assigned to Seattle Mariners. |
| 03/05/26 | SS Axel Sanchez assigned to Seattle Mariners. |
| 03/04/26 | 1B Hogan Windish assigned to Seattle Mariners. |
| 03/03/26 | C Mitch Garver assigned to Seattle Mariners. |
| 03/03/26 | C Connor Dykstra assigned to Seattle Mariners. |
| 03/01/26 | OF Bill Knight roster status changed by Seattle Mariners. |
| 03/01/26 | OF Bill Knight assigned to Seattle Mariners. |
| 03/01/26 | Seattle Mariners signed free agent C Jacob Nottingham to a minor league contract. |