1988 Seattle Mariners season

Offseason

• December 9, 1987: Phil Bradley and Tim Fortugno were traded by the Mariners to the, Clay Parker, and Wade Taylor were traded by the Mariners to the New York Yankees for Steve Trout and Henry Cotto.
• January 19, 1988: John Rabb was signed as a free agent by the Mariners.

  Regular season

• Mark Langston became the ace of the pitching staff as he led the club in wins and strikeouts.

  Opening Day starters

• Mickey Brantley
• Alvin Davis
• Mike Kingery
• Ken Phelps
• Jim Presley
• Rey Quiñones
• Harold Reynolds
• Steve Trout
• Dave Valle
• Glenn Wilson

  Season standings

Record vs. opponents

Notable transactions

• May 23, 1988: John Christensen was released by the Mariners.
• June 1, 1988: Steve Balboni was signed as a free agent by the Mariners.
• June 1, 1988: Greg Pirkl was drafted by the Mariners in the 2nd round of the 1988 Major League Baseball Draft. Player signed June 6, 1988.
• July 21, 1988: Ken Phelps was traded by the Mariners to the New York Yankees for Jay Buhner, Rich Balabon and a player to be named later. The Yankees completed the deal by sending Troy Evers to the Mariners on October 12.
• July 22, 1988: Glenn Wilson was traded by the Mariners to the Pittsburgh Pirates for Darnell Coles.

  Major League debuts

• Batters:
• *Greg Briley
• *Bill McGuire
• Pitchers:
• *Erik Hanson
• *Mike Schooler
• *Terry Taylor

  Roster

Player stats

Batting

Starters by position

Other batters

Pitching

Starting pitchers

Other pitchers

Relief pitchers

Farm system