2025 was a season of triumph for the Seattle Mariners…until it wasn’t. The only franchise in MLB history never to make a World Series, the Mariners came tantalizingly close, blowing a seventh-inning lead to the Toronto Blue Jays in Game 7 of the American League Championship Series. Julio Rodríguez chased a 3-2 slider way down and away with Cal Raleigh, the MVP runner-up, waiting on deck.

Now, the long slog back to get those final nine outs in 2026 is barely underway, and it’s been a slow start, as Seattle is just 11-15, and it hasn’t been above .500 since beating the New York Yankees 2-1 on March 30. The Mariners have a decent opportunity to get on track this weekend with a road series against the St. Louis Cardinals, who missed the playoffs last season. First pitch in tonight’s series opener is scheduled for 8:15 p.m. ET.

Seattle will send George Kirby to toe the rubber, and St. Louis will start Andre Pallante.

Let’s break down this matchup with some odds and lines at DraftKings Sportsbook.

Seattle Mariners at St. Louis Cardinals prediction, preview

The main issue in the Mariners’ malaise has been their offense; they rank just 23rd in OPS so far, and though that’s somewhat typical given their pitcher-friendly ballpark, they finished 10th in that stat last season. Josh Naylor has been the main driver of that struggle, as he’s hit just .194/.269/.280, but Raleigh’s batting average is also below the Mendoza Line. It’s likely that both Raleigh and Naylor will turn it around eventually, and Raleigh already has: in his last eight games, he’s slashed .313/.389/.656 with a trio of homers. Once free agency signing Brendan Donovan returns and Naylor starts hitting, Seattle should be well-suited to start winning, especially since its pitching staff ranks fourth in ERA. Three of the team’s five starters and five of its seven relievers have a sub-3 ERA, and by Pythagorean win-loss, the Mariners should be two games better.

By contrast, the Cardinals have gotten pretty lucky. By Pythagorean win-loss, they should be just 11-13, but they’re actually 14-10. While they rank just 20th in OPS, that’s a step in the right direction relative to last season, when they finished 24th. Most of that improvement has been driven by Jordan Walker, who has a .964 OPS and has slugged eight home runs one season after being one of the worst qualified hitters in baseball, but young shortstop Masyn Winn and rookie second baseman JJ Wetherholt have had promising starts to the season as well. However, St. Louis’ pitching staff hasn’t improved, finishing 21st in ERA in 2025 and ranking 26th so far this season. Closer Riley O’Brien, who ranks second in the NL in saves and hasn’t given up a run in 13.1 innings pitched, has been just about the only bright spot on the staff.

Kirby, a steadily above-average No. 2 starter who sports a 108 ERA+ for his career, has posted the best season of his career so far. He’s provided at least 5.2 innings of work in each start and hasn’t given up more than four runs in any. Advanced numbers paint a pretty positive picture of him: thanks to his 99th-percentile fastball, he ranks in the 92nd percentile in pitching run value. While he still has a few glaring issues, struggling with his breaking balls and posting bottom-quintile average exit velocity, whiff, and hard hit rates, he could be okay against the Cardinals, who have been almost exactly the median team in each category. Plus, he’s great at inducing ground balls, which could exacerbate St. Louis’ tendency to hit it into the ground. He should be able to offer at least six solid innings, especially because the splits are in his favor: the Cardinals have been significantly worse against right-handers and slightly worse at home.

Kirby should have a significant edge in the starting pitching matchup over Pallante, who was worth negative-1.1 WAR last season. To be fair, Pallante has had three good starts in 2026, pitching five innings in each of his starts and giving up two or fewer runs in three of them, but his blow-up was a six-run disaster. Advanced stats aren’t very kind to him; though his breaking pitches have been effective, he ranks below the median in all but three Statcast categories. He’s especially struggled to produce chases or strikeouts, which should be welcome news against an aggressive Seattle lineup. He also issues a lot of walks, and the Mariners have been pretty good at earning free passes. However, he has a few things in his favor: he induces lots of ground balls, and Seattle consistently finds the launch-angle sweet spot, and the Mariners have been awful on the road (a league-worst .531 OPS).

Seattle Mariners at St. Louis Cardinals pick, best bet

Best Bet: Seattle Mariners -1.5 (+119)

Despite each team’s record, Seattle has been the better team this season, and Kirby has a much longer track record of success than Pallante. The Mariners’ pitching should be sustainable, given how strong their staff was last season, and their offense can’t continue to be this impotent on the road.

Strong Lean: Jordan Walker or Cal Raleigh – Either Player 1+ Home Runs (+232)

Big Dumper has gone yard in three straight games and it feels like it’s only a matter of time before he regains sustained solid form. Pallante mostly throws four-seam fastballs to lefties, and Raleigh has a solid .524 slugging percentage against righty four-seamers. Walker, meanwhile, hasn’t gone yard since April 13, but Kirby often throws sliders to righties, and Walker has a 1.333 slugging percentage against right-handed sliders.