Mariners Roster & Staff
Transactions
| Date | Transaction |
| 03/27/25 | Seattle Mariners placed RHP George Kirby on the 15-day injured list retroactive to March 24, 2025. Right shoulder inflammation. |
| 03/27/25 | Seattle Mariners signed free agent RHP Jesse Hahn to a minor league contract. |
| 03/27/25 | Seattle Mariners placed RHP Matt Brash on the 15-day injured list retroactive to March 24, 2025. Right UCL sprain. |
| 03/27/25 | Seattle Mariners signed free agent LHP Drew Pomeranz to a minor league contract. |
| 03/27/25 | Seattle Mariners placed RHP Troy Taylor on the 15-day injured list retroactive to March 24, 2025. Right lat strain. |
| 03/25/25 | Seattle Mariners activated 1B Rowdy Tellez. |
| 03/25/25 | Seattle Mariners selected the contract of 1B Rowdy Tellez from Tacoma Rainiers. |
| 03/24/25 | C Andruw Salcedo assigned to Seattle Mariners. |
| 03/24/25 | CF Kelvin Alcantara assigned to Seattle Mariners. |
| 03/24/25 | 1B Gabriel Moncada assigned to Seattle Mariners. |
| 03/23/25 | Seattle Mariners released RF Mitch Haniger. |
| 03/23/25 | Seattle Mariners optioned SS Leo Rivas to Tacoma Rainiers. |
| 03/23/25 | Seattle Mariners optioned C Blake Hunt to Tacoma Rainiers. |
| 03/23/25 | Seattle Mariners optioned RHP Casey Legumina to Tacoma Rainiers. |
| 03/22/25 | RHP Allan Saathoff assigned to Seattle Mariners. |
| 03/22/25 | Seattle Mariners optioned RF Dominic Canzone to Tacoma Rainiers. |
| 03/22/25 | New York Mets traded RHP Michael Hobbs to Seattle Mariners. |
| 03/22/25 | Seattle Mariners optioned 1B Austin Shenton to Tacoma Rainiers. |
| 03/21/25 | 2B Ricardo Cova assigned to Seattle Mariners. |
| 03/21/25 | Seattle Mariners signed free agent LHP Calvin Schapira to a minor league contract. |
| 03/18/25 | CF George Feliz assigned to Seattle Mariners. |
| 03/16/25 | OF Yoyner Fajardo assigned to Seattle Mariners. |
| 03/16/25 | 2B Dervy Ventura assigned to Seattle Mariners. |
| 03/16/25 | RHP Jordan Jackson assigned to Seattle Mariners. |
| 03/16/25 | RHP Kyle Hill assigned to Seattle Mariners. |
| 03/16/25 | 1B Hunter Fitz-Gerald assigned to Seattle Mariners. |
| 03/16/25 | CF Cesar Quintas assigned to Seattle Mariners. |
| 03/15/25 | RHP Adrian Quintana assigned to Seattle Mariners. |
| 03/15/25 | C Matthew Ellis assigned to Seattle Mariners. |
| 03/15/25 | LHP Matt Cronin assigned to Seattle Mariners. |
| 03/15/25 | CF Victor Labrada assigned to Seattle Mariners. |
| 03/15/25 | RHP Jean Munoz assigned to Seattle Mariners. |
| 03/15/25 | Miami Marlins claimed RHP Seth Martinez off waivers from Seattle Mariners. |
| 03/15/25 | Seattle Mariners optioned 1B Tyler Locklear to Tacoma Rainiers. |
| 03/14/25 | OF Ryan Picollo assigned to Seattle Mariners. |
| 03/14/25 | Seattle Mariners released RHP Neftalí Feliz. |
| 03/14/25 | RHP Anyelo Ovando assigned to Seattle Mariners. |
| 03/14/25 | Seattle Mariners optioned RHP Will Klein to Tacoma Rainiers. |
| 03/13/25 | C Julio E. Rodriguez assigned to Seattle Mariners. |
| 03/13/25 | 3B Austin St. Laurent assigned to Seattle Mariners. |
| 03/12/25 | LF Colin Davis assigned to Seattle Mariners. |
| 03/12/25 | 3B Ben Ramirez assigned to Seattle Mariners. |
| 03/10/25 | Seattle Mariners optioned RHP Cody Bolton to Tacoma Rainiers. |
| 03/08/25 | CF Curtis Washington Jr. assigned to Seattle Mariners. |
| 03/08/25 | SS Axel Sanchez assigned to Seattle Mariners. |
| 03/08/25 | RHP Reid Morgan assigned to Seattle Mariners. |
| 03/07/25 | Seattle Mariners optioned RHP Blas Castano to Tacoma Rainiers. |
| 03/07/25 | Seattle Mariners optioned RHP Hagen Danner to Tacoma Rainiers. |
| 03/06/25 | RHP Travis Kuhn assigned to Seattle Mariners. |
| 03/02/25 | Seattle Mariners released RHP Dauris Valdez. |
| 03/02/25 | Seattle Mariners placed RHP Jackson Kowar on the 60-day injured list. Tommy John surgery recovery. |
| 03/02/25 | Seattle Mariners claimed RHP Seth Martinez off waivers from Miami Marlins. |