Mariners Roster & Staff
Transactions
| Date | Transaction |
| 01/29/10 | Seattle Mariners signed free agent LF Eric Byrnes. |
| 01/29/10 | Seattle Mariners designated 1B Tommy Everidge for assignment. |
| 01/25/10 | Seattle Mariners signed free agent C John Parham to a minor league contract. |
| 01/15/10 | Seattle Mariners claimed 1B Tommy Everidge off waivers from Oakland Athletics. |
| 01/13/10 | Seattle Mariners signed free agent 1B Brad Nelson to a minor league contract and invited him to spring training. |
| 01/07/10 | Boston Red Sox traded 1B Casey Kotchman to Seattle Mariners for Player To Be Named Later and LF Bill Hall. |
| 01/07/10 | Boston Red Sox traded 1B Casey Kotchman to Seattle Mariners for Player To Be Named Later and LF Bill Hall. |
| 01/07/10 | Boston Red Sox traded 1B Casey Kotchman to Seattle Mariners for Player To Be Named Later and LF Bill Hall. |
| 01/06/10 | Seattle Mariners signed free agent SS Chris Woodward to a minor league contract and invited him to spring training. |
| 01/02/10 | Pedro Okuda assigned to VSL Mariners from Seattle Mariners. |
| 01/01/10 | Seattle Mariners signed free agent RHP Seon Gi Kim to a minor league contract. |