Seattle Mariners vs Boston Red Sox Picks, Prediction, Odds, and Line Movement for Tuesday September 1 2026

Seattle Mariners vs Boston Red Sox picks and prediction for Tuesday, September 1, 2026, start with the current matchup, recent form and Tuesday's probable pitchers. Seattle is 64-74, while Boston is 75-63. First pitch is scheduled for 6:45 p.m. EDT at Fenway Park, Boston, Massachusetts. Bettors comparing the rest of Tuesday's card can also visit our MLB picks and predictions.

Best Available Odds for Seattle Mariners vs Boston Red Sox

• Moneyline: Seattle +106 | Boston -124
• Run Line: Seattle +1.5 (-220) | Boston -1.5 (+180)
• Total: Over 7.5 (-102) | Under 7.5 (-120)
• Best Bet: Over 7.5 (-102)

Game Info

• Date: Tuesday, September 1, 2026
• Time: 6:45 p.m. EDT
• Venue: Fenway Park, Boston, Massachusetts
• Probable Pitchers: Bryan Woo (9-9, 4.36 ERA, 142 SO) vs Boston starter TBD

Seattle Mariners vs Boston Red Sox Preview

Monday's opener was one of the wildest games on the slate. Boston erased an 8-5 deficit and beat Seattle 9-8 in 10 innings on Trevor Story's walk-off single. Randy Arozarena had four hits, a homer and four RBIs for Seattle, while Cal Raleigh also homered. Boston answered with a Jarren Duran two-run shot, three RBIs from Ceddanne Rafaela and three RBIs from Story. The result extended Seattle's losing streak to five games and pushed Boston to 75-63.

Recent Form

The score matters more than the winner for Tuesday's handicap because both lineups showed they can create damage from multiple spots. Seattle finally got a big offensive game and still lost because the bullpen could not protect an 8-5 lead. Boston showed the opposite trait: it kept extending innings until the tying and winning runs appeared. Fenway also rewards doubles and line-drive contact, which fits both Arozarena and Boston's group of aggressive gap hitters.

Starting Pitchers

Woo is the only confirmed starter at the latest official check. He is 9-9 with a 4.36 ERA and 142 strikeouts. Boston's starter remains TBD, which is important because it prevents a clean pitching comparison. That uncertainty is one reason the total is preferable to a side. Woo has enough swing-and-miss ability to settle the game down, but Seattle's bullpen just worked a stressful extra-inning loss and may have less flexibility behind him. Pitcher strikeout and hitter markets connected to Tuesday's matchup are also covered on our MLB player props page.

Lineup and Bullpen Outlook

Arozarena's four-hit game was Seattle's best sign, and Raleigh continues to supply power in the middle. Julio Rodriguez and Josh Naylor give the Mariners additional threats if Boston again has to use several relievers. The Red Sox counter with Rafaela, Duran and Story, all of whom were directly involved in Monday's comeback. The bullpen workload is the biggest late-game issue: both clubs used high-leverage arms in a 10-inning game, and neither manager can assume a clean rested bridge from the sixth through the ninth.

Matchup and Betting Trends

Seattle has gone over the total in 69 of 136 betting decisions, while Boston has gone over in 63 of 136. Seattle is also only 50-86 against the spread, a reflection of how often games have gotten away late. Those records support a volatile game environment, especially after Monday's 17-run opener. More team-specific history is available in our MLB betting trends.

Odds and Line Movement

Tuesday's market has been unusually scattered because Boston has not confirmed a starter. Boston has traded around -117 to -124, while totals have appeared from 7.5 to 8.5 across the morning. The current 7.5 with Over -102 is the number to attack. It is lower than the 17-run output Monday and still allows an 5-3 final to cash.

What Will Decide the Game

The first question is whether Woo can give Seattle length after the bullpen-heavy opener. The second is how Boston handles its still-unannounced starter. If either team needs three or four middle-relief innings again, the late scoring ceiling rises quickly. Seattle's offense also needs to prove Monday was not a one-game spike.

Seattle Mariners vs Boston Red Sox Best Bet

Best Bet: Over 7.5 (-102). Over 7.5 at -102 is the Best Bet. Monday produced 17 runs, both bullpens were forced into high-leverage work, and Boston's starting assignment remains unsettled. Woo can pitch well and the game can still reach eight because both lineups are capable of scoring against tired relief. The risk is that Woo dominates and Boston turns to a strong spot starter, but the current number leaves enough room for a 6-4 type of result.

Seattle Mariners vs Boston Red Sox Prediction

The projected final is Boston Red Sox 6, Seattle Mariners 4.

Prediction: Boston Red Sox 6, Seattle Mariners 4