St. Louis Cardinals vs Seattle Mariners Prediction 9/9/2025 Today’s MLB Picks

In this article, we will formulate a Reds vs Padres Prediction for this MLB game on Tuesday, September 9th at the T-Mobile Park in the second game of this series, with the Mariners having the 1-0 lead. Let’s take a look at the prediction for this MLB matchup.

Seattle Mariners Preview

The Seattle Mariners have a 76-68 record this season and are sitting on the second place of the AL West. The Mariners have a 42-27 home record and are 78-60 in over/under. They are coming off a 4-2 home victory over the Cardinals, and have three consecutive wins. Over is 5-2 in their last 7 games and are playing the Angels and the Royals next.

The Mariners have a .243 batting average this season, .319 OBP and .415 Slugging percentage. Seattle’s pitching staff has a 4.00 ERA and 1.25 WHIP. Julio Rodriguez leads the Mariners in hits with 158, and he is the team’s best hitter with a .268 batting average. Cal Raleigh leads the team both in RBI with 113, and in home runs with 53.

George Kirby (R) is the projected starting pitcher for the Mariners, and he has an 8-7 record, 4.47 ERA and 1.23 WHIP.

Saint Louis Cardinals Preview

The Saint Louis Cardinals have a 72-73 record this season and are sitting on the 4th place of the NL Central. The Cardinals have a 31-39 road record and are 72-65 in over/under. They are coming off a 2-4 road defeat by the Mariners, that ended their two-game winning streak. Under is 5-1 in their last 6 games and are playing the Brewers and the Reds next.

The Cardinals have a .245 batting average this season, .314 OBP and .380 Slugging percentage. Saint Louis’ pitching staff has a 4.27 ERA and 1.31 WHIP. Alec Burleson leads the Cardinals with 124 hits, and he is the team’s best hitter with a .286 batting average. Wilson Contreras leads the team in RBI, with 78, adding a team-high 20 home runs.

Matthew Liberatore (L) is the projected starting pitcher for the Cardinals, and he has a 7-11 record, 4.15 ERA and 1.30 WHIP.

St. Louis Cardinals @ Seattle Mariners Betting Trends: September 9, 2025

• Probable Starting Pitcher: George Kirby      Record this season: 8-7      ERA: 4.47
• Home Record: 4-3
• Last 5 against Cardinals: 1-0

Why the Seattle Mariners will win

• The Mariners have won 11 of their last 12 home games against teams that held a losing record.
• The Cardinals have lost eight of their last nine games against American League opponents that held a winning record.
• The Cardinals have failed to cover the run line in six of their last seven night games against AL West opponents that held a winning record.
• The favorites have covered the run line in four of the last five games between the Cardinals and Mariners.
• The Cardinals have lost the first inning in seven of their last nine night games against American League opponents that held a winning record.
• The Mariners have led after 5 innings in four of their last five home games.

• Probable Starting Pitcher: Matthew Liberatore      Record this season: 7-11      ERA: 4.15
• Road Record: 2-6
• Last 5 against Mariners: 0-0

Why the St. Louis Cardinals will win

• The Cardinals have won each of their last five games as underdogs against AL West opponents following a loss.
• The Mariners have lost three of their last four games as favorites following a home win.
• The Cardinals have covered the run line in each of their last seven games against the Mariners following a loss.
• The Mariners have failed to cover the run line in eight of their last nine games as favorites against National League opponents following a home win.
• The Mariners have trailed after 3 innings in six of their last eight night games against National League opponents.
• The Cardinals have led after 5 innings in four of their last five road night games.

Total Runs Facts

• Eight of the Mariners’ last nine home games against NL Central opponents have gone UNDER the total runs line.
• Each of the Cardinals’ last five games after playing the previous day have gone UNDER the total runs line.
• The ‘Inning 1 UNDER 0.5 runs’ market has hit in each of the Mariners’ last six games against NL Central opponents.
• The ‘Inning 1 UNDER 0.5 runs’ market has hit in each of the Cardinals’ last five games against American League opponents.

Seattle Mariners Player Prop Facts

• Cal Raleigh has hit a home run in three of the Mariners’ last four games against opponents that held a losing record.
• George Kirby has recorded seven or more strikeouts in four of his last five appearances against opponents that held a losing record.
• George Kirby has recorded a win in five of his last six appearances against opponents that held a losing record.
• Jorge Polanco has recorded a Double in four of the Mariners’ last five home games against NL opponents.
• Randy Arozarena has recorded at least one hit in each of his last 10 home appearances against former teams.
• Cal Raleigh ranks 1st in the league in Home Runs (53) this season.

St. Louis Cardinals Player Prop Facts

• Alec Burleson has hit a home run in each of the Cardinals’ last three road games against AL opponents that held a winning record.
• Alec Burleson has recorded at least one hit in each of his last 10 road appearances against AL opponents.
• Victor Scott II ranks 10th in the league in Steals (31) this season.

Matchup/League Facts

• The Mariners rank 30th in the league for doubles this season (196).
• The Mariners rank 2nd in the league for home runs this season (210).
• The Cardinals rank 30th in the league for triples this season (7).
• The Cardinals rank 29th in the league for strikeouts this season (1070).

Cardinals vs Mariners Prediction

The Mariners are 5-2 in their last 7 head-to-head meetings against the Cardinals, and are 3-1 in their last 4 meetings in Seattle. Under is 4-2 in their last 6 meetings in Seattle.

In this Cardinals vs Mariners Prediction, the Mariners are coming as -220 home favorites. The Mariners are clearly overpriced in this spot, as both pitchers have almost identical numbers this season, and Kirby has been in terrible form lately for the Mariners. He has a 1-4 record and 5.74 ERA across his last 5 starts, while Liberatore for the Cardinals is coming off a shutout start against the A’s. the Cardinals have a slightly better bullpen ERA, while the Mariners are weaker against left-handed pitching, so I like the value with the big road dog in this one. Take the Saint Louis Cardinals by +1.5 runs to keep this one close on the road.