Mariners Roster & Staff
Transactions
| Date | Transaction |
| 04/14/25 | Seattle Mariners designated RHP Casey Lawrence for assignment. |
| 04/14/25 | Seattle Mariners activated RHP Troy Taylor from the 15-day injured list. |
| 04/13/25 | Seattle Mariners sent RHP Matt Brash on a rehab assignment to Tacoma Rainiers. |
| 04/13/25 | Seattle Mariners transferred 2B Ryan Bliss from the 10-day injured list to the 60-day injured list. Torn left biceps. |
| 04/13/25 | Seattle Mariners optioned RF Dominic Canzone to Tacoma Rainiers. |
| 04/13/25 | Seattle Mariners selected the contract of 3B Ben Williamson from Tacoma Rainiers. |
| 04/12/25 | Seattle Mariners sent RHP Jesse Hahn outright to Tacoma Rainiers. |
| 04/11/25 | Seattle Mariners signed free agent RHP Michael Mariot to a minor league contract. |
| 04/11/25 | Seattle Mariners recalled RHP Casey Legumina from Tacoma Rainiers. |
| 04/10/25 | Seattle Mariners optioned RHP Luis F. Castillo to Tacoma Rainiers. |
| 04/09/25 | Seattle Mariners placed 2B Ryan Bliss on the 10-day injured list. Left biceps tear. |
| 04/09/25 | Seattle Mariners designated RHP Jesse Hahn for assignment. |
| 04/09/25 | Seattle Mariners selected the contract of RHP Casey Lawrence from Tacoma Rainiers. |
| 04/09/25 | Seattle Mariners recalled SS Leo Rivas from Tacoma Rainiers. |
| 04/08/25 | Seattle Mariners traded RHP Cody Bolton to Cleveland Guardians for cash. |
| 04/07/25 | Seattle Mariners placed CF Victor Robles on the 10-day injured list. Left shoulder dislocation. |
| 04/07/25 | Seattle Mariners recalled RF Dominic Canzone from Tacoma Rainiers. |
| 04/07/25 | Seattle Mariners sent RHP Hagen Danner outright to Tacoma Rainiers. |
| 04/05/25 | Seattle Mariners designated RHP Cody Bolton for assignment. |
| 04/05/25 | Seattle Mariners selected the contract of RHP Jesse Hahn from Tacoma Rainiers. |
| 04/05/25 | Seattle Mariners optioned LHP Tayler Saucedo to Tacoma Rainiers. |
| 04/04/25 | Seattle Mariners designated RHP Hagen Danner for assignment. |
| 04/04/25 | Seattle Mariners selected the contract of RHP Luis F. Castillo from Tacoma Rainiers. |
| 04/03/25 | Seattle Mariners activated 2B Jorge Polanco from the paternity list. |
| 04/03/25 | Seattle Mariners optioned LHP Jhonathan D¨Şaz to Tacoma Rainiers. |
| 04/03/25 | Seattle Mariners optioned SS Leo Rivas to Tacoma Rainiers. |
| 04/01/25 | Seattle Mariners placed 2B Jorge Polanco on the paternity list. |
| 04/01/25 | Seattle Mariners signed free agent RHP William Fleming to a minor league contract. |
| 04/01/25 | Seattle Mariners sent RHP Troy Taylor on a rehab assignment to Tacoma Rainiers. |
| 04/01/25 | Seattle Mariners selected the contract of LHP Jhonathan D¨Şaz from Tacoma Rainiers. |
| 04/01/25 | Seattle Mariners optioned RHP Emerson Hancock to Tacoma Rainiers. |
| 04/01/25 | Seattle Mariners recalled SS Leo Rivas from Tacoma Rainiers. |