Seattle Mariners vs Boston Red Sox Picks and Prediction for Wednesday September 2 2026

The Seattle Mariners visit the Boston Red Sox on Wednesday, September 2, at Fenway Park in Boston, Massachusetts. First pitch is scheduled for 4:10 PM ET with MLB.TV providing coverage. Seattle enters at 64-74 overall and 27-43 on the road, while Boston is 75-63 overall and 35-32 at home. The Mariners have lost five consecutive games, while the Red Sox snapped a difficult stretch with a 9-8 extra-inning victory over Seattle in the first completed game of this series. ESPN Analytics gives Boston a 63.0% chance to win compared with 37.0% for Seattle. At the time of this writing the odds were not released. Check out our free MLB picks for more baseball predictions throughout the season.

Starting Pitchers

Bryce Miller is scheduled to start for Seattle and enters at 4-8 with a 4.12 ERA and 1.09 WHIP across 94 innings. He has allowed 77 hits while recording 92 strikeouts against 25 walks and has surrendered 17 home runs. Patrick Sandoval gets the assignment for Boston and enters at 1-3 with a 4.20 ERA and 1.71 WHIP across 45 innings. He has allowed 55 hits with 48 strikeouts, 22 walks and six home runs. The ERA numbers are nearly identical, but Seattle owns the advantage in WHIP and overall baserunner prevention from its scheduled starter.

Mariners Try to Stop Five-Game Slide

Seattle enters Wednesday at 64-74 overall and just 27-43 on the road. The Mariners sit third in the AL West, six games behind Houston, and their recent slide has damaged their position entering September. Seattle has lost five consecutive games, including a painful 9-8 extra-inning defeat at Fenway Park in the first completed game of this series. The Mariners were also swept in Toronto immediately before arriving in Boston, losing those three games by scores of 8-1, 4-3 and 7-0.

The Mariners are batting .227 with 538 runs, 1,035 hits and 159 home runs. They own a .308 on-base percentage and .374 slugging percentage. Those numbers reveal Seattle's primary problem, as Boston holds significant advantages in batting average, runs, hits, on-base percentage and slugging percentage. Seattle does possess more home-run power, but the Mariners have struggled to consistently turn that power into enough offense, scoring 80 fewer runs than Boston this season.

Seattle's pitching staff carries a 4.18 ERA and 1.25 WHIP while opponents are batting .250. The Mariners have issued 364 walks and recorded 1,163 strikeouts. Their pitching numbers are respectable enough to keep games competitive, but they trail Boston in ERA, WHIP and opponent batting average. The scheduled pitching matchup gives Seattle some reason for optimism, but the combination of a five-game losing streak, a 27-43 road record and an inconsistent offense creates a difficult setup at Fenway Park.

Red Sox Have the Offensive Advantage

Boston enters Wednesday at 75-63 overall and 35-32 at Fenway Park. The Red Sox are third in the AL East, 7.5 games behind Tampa Bay and three games behind New York. Their recent form has been uneven, with Boston going 2-3 over its last five games, but Monday's 9-8 extra-inning win over Seattle was important after consecutive losses in New York. The Red Sox now have an opportunity to build momentum against a Seattle club that has not won since August 25.

The Red Sox are batting .249 with 618 runs, 1,154 hits and 140 home runs. Boston owns a .323 on-base percentage and .405 slugging percentage. The Red Sox have scored 80 more runs than Seattle while producing 119 more hits, and their 22-point advantage in batting average is significant this deep into the season. Seattle has hit 19 more home runs, but Boston's overall offensive profile has been considerably more productive.

Boston also holds the advantage in the broader pitching numbers with a 3.60 ERA, 1.23 WHIP and .241 opponent batting average. The Red Sox have recorded 1,179 strikeouts while issuing 397 walks. Their scheduled starter's 1.71 WHIP creates some concern Wednesday, particularly against a Seattle lineup capable of hitting for power, but Boston's full-season pitching performance has been considerably stronger. The combination of better offense, better team run prevention and home-field advantage gives the Red Sox the stronger overall profile.

Seattle Mariners vs Boston Red Sox Picks and Prediction

Pick: Boston Red Sox Moneyline

The Boston Red Sox Moneyline is the preferred side. Seattle has an advantage in the starting pitching matchup when comparing WHIP, but virtually every broader indicator points toward Boston. The Red Sox have the better overall record, stronger home-road split for this matchup, substantially better offensive numbers and a superior team pitching profile. Seattle has lost five straight and is only 27-43 away from home, while Boston already opened this series with a victory. ESPN Analytics also gives the Red Sox a 63.0% win probability. Take the Boston Red Sox Moneyline.

Pick: Over 8.5

The Over 8.5 is the preferred total if the market settles around that number. Boston's scheduled starter carries a 1.71 WHIP and has allowed 55 hits plus 22 walks in only 45 innings, creating opportunities for Seattle despite the Mariners' season-long offensive struggles. Boston should also have scoring opportunities against a Seattle staff carrying a 4.18 ERA and .250 opponent batting average. The first completed game of this series produced 17 runs in Boston's 9-8 extra-inning victory, and the starting pitching matchup leaves enough vulnerability on both sides to support another higher-scoring game. Take the Over if the total is set at 8.5.

Final Picks: Boston Red Sox Moneyline and Over 8.5

This preview was completed before play on Tuesday. Starting pitchers, betting lines and other game information are subject to change before the game begins.