Seattle Mariners face Boston Red Sox in series opener at Fenway Park

The Seattle Mariners travel to Boston to begin a three-game series against the Red Sox on August 31, 2026. This matchup follows a series for the Mariners in Toronto. For the Red Sox, the game takes place at Fenway Park during the club's scheduled Heated Rivalry Night. Roster changes precede the contest, as the Red Sox activated Cooper Criswell from the 60-day injured list. Conversely, the team placed Nick Davila on the injured list citing an SC joint sprain. Brendan Donovan was observed taking grounders at third base ahead of the game. First pitch is scheduled for 3:45 p.m. PT, with broadcast coverage provided by Mariners TV and 710 AM Seattle Sports radio.

• 10:38 PMYahoo Sports — Mariners Game #138 Preview and Discussion: 8/31/26, Mariners at Red Sox