Mariners vs. Astros: Game 3 prediction, odds, injuries, and picks - September 21, 2025

The AL West limelight is shining brightly in Houston Sunday night as the Seattle Mariners look to extend their three-game road winning streak against the Astros.

Seattle has come alive late in the season, going 9-1 in their past 10 games behind a shut-down pitching staff, while Houston has used its depth to stay in division contention after losing some of its bigger guns.

With the Mariners up only 7-5 in the season series, this season finale not only settles bragging rights, but could also become significant in the battle for playoff positioning.

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Starting Pitchers

Logan Gilbert - Seattle Mariners

Gilbert takes the mound for Seattle, coming off a strong season in terms of strikeouts and command. Over 120 innings, he’s struck out 164 batters with a 3.53 ERA and 1.05 WHIP, showing an ability to limit free passes and induce weak contact. If he can maintain early control and navigate Houston’s middle order, Gilbert gives the Mariners a solid chance to continue their road win streak and set the tone for a tight matchup.

Jason Alexander - Houston Astros

Alexander will start for Houston, carrying a 4-1 record with a 4.04 ERA and 1.30 WHIP over 71.1 innings. He has 60 strikeouts and 1 save on the year, demonstrating strikeout upside but also some vulnerability when hitters put the ball in play. Alexander will need to rely on location and sequencing to keep Seattle’s hot lineup in check and give the Astros a shot at evening the series.

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Hot Hitters

Cal Raleigh (SEA) - Franchise-record power this season; the long ball is the simplest way Seattle breaks a tie.

Jose Altuve / Jeremy Pena (HOU) - Veterans who produce in key spots and can turn a one-run game into a multi-run inning with extra-base hits.

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Injury Report

Astros:

• Kaleb Ort – Elbow (60-Day IL)
• Yordan Alvarez – Ankle (10-Day IL)
• Lance McCullers – Hand (15-Day IL)
• Luis Garcia – Elbow (60-Day IL)
• Spencer Arrighetti – Elbow (15-Day IL)
• John Rooney – Concussion/Nasal (60-Day IL)
• Brendan Rodgers – Oblique (60-Day IL)
• Pedro Leon – Knee (60-Day IL)
• Brandon Walter – Elbow (60-Day IL)
• Bennett Sousa – Elbow (15-Day IL)
• Josh Hader – Shoulder (15-Day IL)
• Zach Dezenzo – Hand (60-Day IL)
• Ronel Blanco – Elbow (60-Day IL)
• Hayden Wesneski – Elbow (60-Day IL)

Mariners:

• Bryan Woo – Pectoral (Day-to-Day)
• Jackson Kowar – Shoulder (15-Day IL)
• Trent Thornton – Achilles (60-Day IL)
• Logan Evans – Elbow (15-Day IL)
• Gregory Santos – Knee (60-Day IL)
• Ryan Bliss – Biceps (60-Day IL)

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Current Odds

• Run Line: Mariners −1.5 (+114) / Astros +1.5 (−139)
• Total: Over 8 (−115) / Under 8 (−105)
• Moneyline: Mariners −143 / Astros +118

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Best Bets & Predictions

1. Mariners Moneyline (−143)
2. Over 8 (−115)
3. Mariners −1.5 (+114)

Final score prediction: Mariners 6, Astros 4