Mariners Roster & Staff
Transactions
| Date | Transaction |
| 01/26/18 | Seattle Mariners signed free agent C Alexander Capriata to a minor league contract. |
| 01/19/18 | Seattle Mariners claimed Chasen Bradford off waivers from New York Mets. |
| 01/16/18 | Seattle Mariners signed free agent RHP Casey Lawrence to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster C Joe DeCarlo to spring training. |
| 01/16/18 | Seattle Mariners signed free agent RHP Johendi Jiminian to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners signed free agent 2B Gordon Beckham to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster C Tuffy Gosewisch to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster RHP Matthew Festa to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster RHP Art Warren to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster RHP Ljay Newsome to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster 3B Jordan Cowan to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster CF Braden Bishop to spring training. |
| 01/16/18 | Seattle Mariners signed free agent OF John Andreoli to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners signed free agent 2B Rey Navarro to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners signed free agent 1B Matt Hague to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster C Joseph Odom to spring training. |
| 01/16/18 | Seattle Mariners signed free agent RHP Christian Bergman to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster RHP Ryan Garton to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster LF Ian Miller to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster RF Andrew Aplin to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster SS Zach Vincej to spring training. |
| 01/16/18 | Seattle Mariners invited non-roster RHP Ryan Cook to spring training. |
| 01/16/18 | Seattle Mariners signed free agent RF Kirk Nieuwenhuis to a minor league contract and invited him to spring training. |
| 01/16/18 | Seattle Mariners signed free agent P Elbis Afanador to a minor league contract. |