The Seattle Mariners host the St. Louis Cardinals on September 8, 2025. First pitch from T-Mobile Park is scheduled for 9:40 p.m. EDT; the game will be broadcast on FDSMW.
Find my MLB betting preview and Cardinals vs Mariners prediction with odds below, as well as probable pitchers, betting trends, injury reports and more.
My Cardinals vs Mariners Prediction
- Cardinals vs Mariners picks: Under 7.5 (-112) | Play to -122
My Cardinals vs Mariners prediction is on the under. Make sure to find the best odds by checking our live MLB odds page.
Cardinals vs Mariners Odds
| Cardinals Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
+1.5 -110 | 7.5 -110o / -110u | +190 |
| Mariners Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
-1.5 -110 | 7.5 -110o / -110u | -235 |
Cardinals vs Mariners Projected Starting Pitchers
| RHP Miles Mikolas (STL) | Stat | RHP Bryan Woo (SEA) |
|---|---|---|
| 7-10 | W-L | 12-7 |
| 0.4 | fWAR (FanGraphs) | 3.0 |
| 4.89/5.46 | ERA /xERA | 3.02/3.15 |
| 4.96/4.91 | FIP / xFIP | 3.66/3.57 |
| 1.33 | WHIP | 0.97 |
| 9.0% | K-BB% | 20.1% |
| 39.6% | GB% | 40.4% |
| 89 | Stuff+ | 104 |
| 107 | Location+ | 109 |
Kenny Ducey’s Cardinals vs Mariners Preview
St. Louis Cardinals Betting Preview: Mikolas Struggles on the Road a Concern
Miles Mikolas has looked great over his last two outings, but now he'll head back on the road — something that's been a source of anguish for him. The right-hander owns a 3.40 ERA in 14 starts at home, but away from St. Louis, that number has skyrocketed to 6.79 with a massive 54-point jump in WHIP as well.
He's an easy man to figure out, standing as one of the worst strikeout pitchers in baseball. The numbers on contact look incredibly poor, but he's been able to limit the damage with a low walk rate and the help of his friendly home park, which has done well to kill all the well-struck fly balls he's allowed this season.
Mikolas has surrendered 17 runs" target="_blank" rel="noopener">homers on the road this season, and while Seattle isn't a traditional home run park, it does technically grade out a good bit easier to his a homer than Busch Stadium in St. Louis. The Mariners also own a solid 13.5% home run-to-fly ball ratio at home this season, which is a top-10 mark, and their Isolated Power for the last two weeks stands at a menacing .218.
Seattle Mariners Betting Preview: Woo Aiming for Recovery at T-Mobile Park
Bryan Woo was on an excellent trajectory before his somewhat flat start in Tampa last week against the Rays. He struck out just three over five frames, surrendering four hits, including a home run, to go along with three walks, making a firm step backwards following a month of progress.
Woo's .201 Expected Batting Average and .333 Expected Slugging in August led him to his best month of the season. His whiff rate may have stayed in a more or less unassuming spot at 25.1%, but his expected numbers dropped for a third straight month — as did his walk rate. We saw the best version of this talented righty we've seen in arguably over a year, but the catch is that he made four of his five starts at home.
As a fellow fly-baller, Woo's been able to utilize T-Mobile Park to his advantage, and the solid strikeout and walk numbers have only made him trickier to hit. Now, he draws a Cardinals team that has displayed nothing in these three areas, running a .129 ISO in the last two weeks with the third-worst strikeout-to-walk ratio in the game over that time.
Cardinals vs Mariners Prediction, Pick
The question here isn't whether or not Woo will dominate the Cardinals; it's whether or not Mikolas will be able to succeed against a Mariners team that is slugging the lights out and hitting .265 over the last two weeks.
They've been a far tamer team at home, losing almost 20 points off their ISO, but they've still graded out as a borderline top-10 offense. Seattle hasn't been at its best offensively in the second half, but it seems to be waking up at the wrong time for Mikolas.
Given the strong projection for Woo, I believe it would take a catastrophe for the Over to cash here. Mikolas has done well to avoid those this season despite his rocky numbers, surrendering five or more runs just six times in 27 outings. We also know he pitches well inside parks that favor fly-ball pitchers, and while Seattle's isn't quite as forgiving, it's still going to help Mikolas.
I wouldn't expect a pitcher's duel here, but I'm also not predicting the Mariners to hit this total by their lonesome, given the numbers all year at home.
Pick: Under 7.5 (-112) | Play to -122
Moneyline
I'm making no bets on the Moneyline
Run Line (Spread)
I'm also making no moves on the Spread
Over/Under
I'm taking the under in this matchup
Cardinals vs Mariners Betting Trends
