With a loss last night and the Astros’ recent three-game winning streak, the Mariners once again find themselves relegated to the American League’s final Wild Card spot. While we should have a much clearer picture of the AL West standings by the end of the weekend, with Seattle visiting Houston for a crucial series, the Mariners have to be careful not to look too far ahead. Every remaining contest is important, including this afternoon’s tilt with the reeling Royals.
Let’s preview this matinee matchup with the help of some of those odds and lines on the DraftKings Sportsbook.
Mariners vs. Royals prediction, preview
Luis Castillo has been far more inconsistent in 2025 than we’ve seen in some time, as the veteran RHP’s 4.31 xERA is the highest it’s been since all the way back in his sophomore campaign in 2018. Still, Castillo has come up big when it’s mattered most, piecing together back-to-back quality starts in his last two appearances against the Braves and the Angels. Castillo isn’t a below-average pitcher by any means, but it is clear that his stuff is diminishing. The 32-year-old’s average fastball velocity is down for the fifth-straight season and that’s translated into career-low marks in strikeout rate (21.3%) and swinging strike rate (11.4%). Castillo is also giving up a career-high 10.6% opponent barrel rate. At the same time, Castillo sports a 3.76 ERA across 167.1 innings. He isn’t an “ace” anymore, yet he’ll remain a huge part of Seattle’s rotation in the postseason.
Speaking of diminished stuff, it’s time to break down Stephen Kolek. Saying that Kolek isn’t a flashy pitcher would be a massive understatement. The 28-year-old very much finds himself in the Kyle Hendricks mold, as someone who relies more on inducing soft contact and deception than overpowering opposing bats. Kolek has been able to generally keep the ball on the ground in 2025, as evidenced by an 87th percentile ground ball rate (51.3%), yet that’s about the only positive thing I can say about the man’s campaign. To be blunt, Kolek is playing with fire. That’s the lone way to view the combination of a fifth percentile whiff rate (17.9%) and a third percentile opponent hard hit rate (48.7%). Kolek’s allowed just four earned runs in his last 19.2 innings, but at some point, he’s going to get burned.
Thursday does not present an easy matchup for Kansas City’s RHP, either. The Mariners are red-hot with their bats at the moment, leading all teams since September 1 in home runs (28), ISO (.233) and wRC+ (138). As you would expect, it’s been Cal Raleigh doing most of the recent damage, as the backstop makes a final push for AL MVP. Raleigh hit his 55th and 56th home runs of the season on Tuesday and he’s slashing .305/.423/.661 in the month.
Mariners vs. Royals pick, best bet
Best Bet: Mariners ML (-126)
Seattle has the pitching edge and the far hotter lineup. The fact they’re even this close to a pick’em is a blessing and opportunity for bettors.
