St. Louis Cardinals vs Seattle Mariners Picks and Prediction, September, 9, 2025
The St. Louis Cardinals face the Seattle Mariners with both teams on opposite ends of the standings in the final weeks of the season. The Cardinals are 72-72 and hovering around .500 all season, leaving them on the outside of the wild card position in the National League by a few games. The Mariners are 75-68, and (with back-to-back wins,) they are clinging to the final wild card spot in the American League. Who will win this game? Check out our Cardinals vs Mariners prediction!
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Cardinals hope Liberatore and lineup step up
The Cardinals look poised to miss the postseason in part because of their rotation issues. One of the starters having a rough season is Matthew Liberatore, who has allowed 70 runs in 136 innings pitched. Moreover, with a .457 expected opponent Slugging Percentage, a 9.6 Barrel Percentage, and a 4.60 expected ERA, opponents are making hard contact and driving in runs at will against Liberatore this season.
Liberatore has struggled this season but the lineup has also been a disappointment, scoring only 4.32 runs per game. Ivan Herrera is slashing .283/.363/.450 with 14 home runs and 145 total bases, while Willson Contreras is slashing .254/.338/.448 with 20 home runs and 212 total bases but the rest of the lineup has struggled. Only four active batters have an OPS+ over 10,0 and opposing pitchers can limit the top-heavy batting order as a result.
Seattle hopes lineup helps out Kirby
The Mariners are having a great season and look for a strong finish to secure a spot in the postseason. George Kirby will start the upcoming game, and he looks to improve on what’s been a rough season as he’s allowed 53 runs in 104.2 innings pitched. In addition, with a .419 expected opponent Slugging Percentage, a 43.4 Hard Hit Rate, and a 4.10 expected ERA, opponents are making hard contact and driving in runs with ease against Kirby.
Kirby has struggled but the lineup has carried the Mariners, scoring 4.66 runs per game with 28 runs in the last three games. Cal Raleigh is slashing .243/.351/.581 with 53 home runs and 306 total bases while Jorge Polanco is slashing .258/.323/.479 with 24 home runs and 194 total bases but the rest of the lineup has stepped up as well. Julio Rodriguez is slashing .267/.318/.479 with 30 home runs and 280 total bases while Dominic Canzone and Randy Arozarena have added 33 home runs and 325 total bases to round out the lineup.
St. Louis Cardinals vs Seattle Mariners Pick
| # | Handicapper | Profit |
|---|---|---|
| 1 |  Rob Vinciletti | +1,570.00 |
| 2 |  Dan Kaiser | +1,223.00 |
| 3 |  Ross Benjamin | +1,000.00 |
| 4 |  Earle Sports Bets | +916.00 |
| 5 |  David Hess | +706.00 |
Spread Pick for St. Louis Cardinals vs Seattle Mariners
- Mariners -1.5 (-110) (4 Units)
The Mariners are inching closer to a spot in the postseason, and they look to take over this game from the first inning. The Mariners, who average 4.66 runs per game, should constantly plate baserunners with Cal Raleigh, Julio Rodriguez, and the rest of the batting order making contact and putting together strong plate appearances. The Mariners should limit the Cardinals lineup, which averages only 4.32 runs per game, with George Kirby stepping up on the mound and pitching multiple scoreless innings to allow the bullpen to close out the game with a lead. The Mariners should win the game and cover the spread in a dominant win at home.
- Over/Under Pick for Cardinals vs. Mariners
- Over 7.5 (5 Units)
Both starting pitchers have struggled, and this game looks to be a high-scoring one from the first pitch. The Cardinals should constantly plate baserunners against George Kirby, who has allowed 53 runs in 104 innings pitched, with Ivan Herrera, Willson Contreras, and the rest of the batting order making contact and putting together strong plate appearances. The Mariners, who have scored 28 runs in their last three games, should run up the score against Matthew Liberatore, who has allowed 70 runs in 136 innings pitched, with Cal Raleigh, Julio Rodriguez, Jorge Polanco, and the rest of the batting order swinging for the fences and crushing pitches to easily circle the bases. The Over should cover in a high-scoring game with both lineups stepping up.
Take the Over on 7.5 runs.
The Cardinals face the Mariners with both teams on opposite ends of the standings to close out the season.
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