Mariners vs. Astros Betting Lines, Odds, & Player Matchups September 21, 2025

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Data Skrive

The Seattle Mariners (86-69) ride a three-game winning streak into a road contest against the Houston Astros (84-71) on Sunday at 7:10 p.m. ET. The Mariners are favored (-139) over the Astros (+118). Seattle’s Logan Gilbert and Houston’s Jason Alexander will start this matchup.

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Moneyline

Mariners to win vs Astros -139

Bet $20, Payout $34.39

Mariners vs. Astros betting lines

  • Favorite: Mariners (-139)
  • Underdog: Astros (+118)
  • Over/under: 8

Mariners betting info, hitting leaders, & pitching

Mariners betting info

  • The Mariners have been the moneyline favorite 107 total times this season. They’ve finished 62-45 in those games.
  • Seattle has a record of 38-21 when it has played as moneyline favorites with odds of -139 or shorter (64.4% winning percentage).
  • The Mariners have an implied moneyline win probability of 58.2% in this contest.
  • In the 155 games in which oddsmakers have set an over/under for Seattle, it has combined with opponents to go over the total 84 times (84-66-5).
  • The Mariners have gone 67-88-0 against the spread this season.

Mariners hitting info

  • Cal Raleigh has racked up a team-high 57 home runs and 119 runs batted in.
  • Raleigh ranks first in home runs and third in RBI among all batters in MLB action.
  • Julio Rodriguez is batting .269 with 31 doubles, four triples, 31 home runs and 39 walks.
  • Rodriguez ranks 15th in homers and 19th in RBI this year.
  • Rodriguez has safely hit in two straight games. During his last five outings he is batting .250 with a double, a home run, two walks and three RBIs.
  • Josh Naylor paces the Mariners with a .289 batting average.
  • Naylor takes a seven-game hitting streak into this game. During his last 10 outings he is batting .366 with a double, two home runs, three walks and nine RBIs.
  • Eugenio Suarez is batting .230 with 28 doubles, 47 home runs and 45 walks.
  • Suarez enters this game on a two-game hitting streak. During his last five outings he is batting .350 with three doubles, two home runs, a walk and four RBIs.

Mariners pitching rankings

  • The 8.7 strikeouts per nine innings compiled by the Mariners pitching staff ranks 10th in MLB.
  • Seattle has the 13th-ranked team ERA across all MLB pitching staffs (3.90).
  • The Mariners have the eighth-lowest WHIP in baseball (1.235).
  • Mariners pitchers combine to give up the 16th-fewest home runs in baseball (184 total, 1.2 per game).
  • In its 6-4 win last time out, Seattle struck out 11 Astros batters while allowing 10 hits.

Astros betting info, hitting leaders, & pitching

Astros betting info

  • The Astros have entered the game as underdogs 55 times this season and won 32, or 58.2%, of those games.
  • This season, Houston has won 16 of its 24 games, or 66.7%, when it’s the underdog by at least +118 on the moneyline.
  • The moneyline for this contest implies a 45.9% chance of a victory for the Astros.
  • Houston and its opponents have gone over the total this season in 70 of its 155 opportunities.
  • The Astros are 78-77-0 against the spread in their 155 chances this season.

Astros hitting info

  • Jose Altuve is batting .263 this season with a team-high 26 home runs.
  • Among all hitters in the big leagues, Altuve’s home run total is 39th, and his RBI total is 64th.
  • Jeremy Pena’s batting average of .304 leads all Houston hitters this season.
  • Pena ranks 108th overall in homers and 102nd in RBI this season.
  • Yainer Diaz has 133 hits this season and a slash line of .258/.287/.417.
  • Carlos Correa is batting .276 with an OBP of .329 and a slugging percentage of .403 this season.
  • Correa has safely hit in five games in a row. In his last five games he is batting .318 with two doubles.

Astros pitching rankings

  • The Astros have a 9.4 K/9 this season as a pitching staff, first-best in baseball.
  • Houston pitchers have a combined ERA of 3.85 ERA this year, eighth-best in baseball.
  • The Astros have a combined WHIP of just 1.225 as a pitching staff, which is the sixth-best in baseball this season.
  • With 190 homers allowed, the Astros rank 22nd in the league at preventing long balls.
  • Houston suffered a 6-4 defeat in its most recent game, as its pitchers struck out nine Mariners batters while allowing nine hits.
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