Explore the Cardinals vs Mariners Matchup Preview and Game Analysis – Tuesday, September 9, 2025

St. Louis Cardinals

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Seattle Mariners

The Seattle Mariners will host the St. Louis Cardinals on September 9, 2025, marking the second game in their interleague series. In the current standings, the Mariners sit at 76-68, displaying an above-average season, while the Cardinals are slightly below .500 at 72-73. This matchup comes after the Mariners secured a win against the Cardinals in their last game, showcasing their momentum.

Seattle’s George Kirby is scheduled to take the mound, and he brings a solid profile with a 4.47 ERA and a 3.54 xFIP, indicating he’s been somewhat unlucky this year. Kirby’s Power Rankings place him as the 36th best starter, and he has shown the ability to pitch 6.1 innings while allowing just 2.1 earned runs on average, indicative of his potential. On the other hand, St. Louis will counter with Matthew Liberatore, who has struggled to find his rhythm. With a 4.15 ERA and an average projection to pitch only 5 innings while allowing 2.6 earned runs, Liberatore’s low strikeout rate could be problematic against a Mariners offense that ranks 12th overall and is particularly dangerous with the long ball, ranking 2nd in MLB for home runs.

Further analysis indicates that Seattle’s bullpen stands at a solid 10th best, giving them an edge late in games. Meanwhile, St. Louis’s offense has been underwhelming, ranking 23rd overall and 26th in home runs, which could hinder their run production.

With a high implied team total of 4.40 runs for the Mariners and a low total of 3.10 for the Cardinals, this game shapes up favorably for Seattle. The projections suggest that the Mariners will continue their strong play, and Kirby’s matchup against the Cardinals’ struggling offense presents a ripe opportunity for the Mariners to assert their dominance once again.

St. Louis Cardinals Insights

• Matthew Liberatore – Over/Under 15.5 Pitching Outs (+160/-210)
  Taking into account both his underlying tendencies and the matchup, Matthew Liberatore is projected to throw 83 pitches in this outing by the leading projection system (THE BAT X) system, which is the 9th-least of all pitchers today.
  Explain: Pitchers who throw relatively few pitches are more likely to get pulled from the game earlier, record fewer outs, and generate fewer strikeouts.
• Lars Nootbaar – Over/Under 0.5 Total Bases (-180/+140)
  Based on Statcast data, the leading projection system (THE BAT X)’s version of Expected HR per 600 plate appearances (23.1) may lead us to conclude that Lars Nootbaar has had some very poor luck this year with his 15.2 actual HR/600.
  Explain: xHR uses highly advanced Statcast data to measure a player’s home run ability more accurately than actual home runs can.
• The St. Louis Cardinals have 4 bats in their projected batting order today with a high (i.e. over 27%) underlying K% (via the leading projection system, THE BAT X) (Nolan Gorman, Willson Contreras, Thomas Saggese, Pedro Pages).
  Explain: Teams that have multiple high-strikeout hitters will make it much easier for the opposing pitcher to record strikeouts

Seattle Mariners Insights

• George Kirby – Over/Under 6.5 Strikeouts (+120/-155)
  George Kirby’s four-seamer utilization has fallen by 5.7% from last season to this one (33.9% to 28.2%) .
  Explain: Fastballs are the one easiest pitches to hit and generate few strikeouts, so a pitcher who begins to use his fastball lessoften will likely be more effective than he used to be.
• J.P. Crawford – Over/Under 0.5 Hits (-130/+100)
  J.P. Crawford has primarily hit in the top-half of the batting order this year (55% of the time), but he is projected to hit 9th on the lineup card in today’s game.
  Explain: The lower in the order a player bats, the fewer plate appearances he will get and the fewer opportunities he will get to hit the Over for every market. A player who hits lower in the order than he normally does may provide extra value opportunity since the market may be based on him hitting higher.
• The 9.6% Barrel% of the Seattle Mariners ranks them as the #7 club in the game this year by this metric.
  Explain: Barrel% measures how often a player hits the ball at the optimal exit velocity and launch angle and is a terrific measure of underlying power.

Betting Trends

• Over/Under 7.5 Game Total (-110/-110)
  The Seattle Mariners have hit the Game Total Over in 74 of their last 132 games (+14.60 Units / 10% ROI)
• St. Louis Cardinals – Over/Under 1.5 1st Five Innings (F5) Team Total (+100/-130)
  The St. Louis Cardinals have hit the 1st Five Innings (F5) Team Total Under in 57 of their last 99 games (+9.20 Units / 8% ROI)
• Josh Naylor – Over/Under 0.5 Total Bases (-170/+130)
  Josh Naylor has hit the Total Bases Over in 13 of his last 15 games at home (+11.80 Units / 54% ROI)