Offseason
- November 13, 1997: Jalal Leach was signed as a Free Agent with the Seattle Mariners.
- December 3, 1997: Ken Huckaby was signed as a Free Agent with the Seattle Mariners.
- December 16, 1997: Pat Listach was signed as a Free Agent with the Seattle Mariners.
- December 27, 1997: Rico Rossy was signed as a Free Agent with the Seattle Mariners.
- January 8, 1998: Glenallen Hill signed as a Free Agent with the Seattle Mariners.
- January 29, 1998: Jalal Leach was traded by the Seattle Mariners with Scott Smith (minors) to the San Francisco Giants for David McCarty.
Read more about this topic: 1998 Seattle Mariners Season