It’s impossible to figure out the 2026 Seattle Mariners.
After seemingly building up a lead they would not relinquish in the jumbled AL West, the Mariners immediately got swept by the Marlins this week in Miami. Yes, the offense has struggled to consistently produce runs, but Seattle’s pitching staff is so good, it’s justifiably using a six-man rotation at the moment. This is not a roster that should be .500.
Can the club get back on track against the American League leading Rays? Let’s preview this clash and make a couple picks on the DraftKings Sportsbook.
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Mariners vs. Rays prediction, preview
If there had been a weak link in that aforementioned six-man rotation, it was Luis Castillo, who comes into tonight’s contest in possession of an inflated 4.79 ERA in 2026. However, the veteran RHP’s last seven appearances have been amazing — a couple have come out of the bullpen in a “piggyback” role. Since May 25, Castillo sports a 2.72 ERA and a 2.92 FIP over 36.1 innings. The 19.5% strikeout rate in this span does leave a little to be desired, but Castillo’s stuff still passes the ol’ eye test. Heck, Castillo’s sinker touched 97.8 mph in his last outing against the Blue Jays. The 33-year-old has some juice left in the tank.
It’s a little ironic that Castillo’s pitching opposition on Friday is Nick Martinez. Whereas Castillo is underperforming his expected statistics this season, Martinez is laughing in the face of regression each and every time he takes the ball. Over 17 starts and exactly 100.0 innings, the soon-to-be 36-year-old has maintained a sterling 2.61 ERA — the third-lowest qualified mark in the AL, trailing only Cam Schlittler and Dylan Cease. However, Martinez’s Baseball Savant page is far less enthusiastic. Martinez owns an eighth percentile opponent expected batting average (.281) and a sixth percentile strikeout rate (15.0%). You’d have to imagine, at some point, Martinez’s .269 opponent BABIP rises and his 85.3% strand rate falls, and he begins looking more like his 4.69 xERA suggests he will. That said, we’re in the midst of a very “Rays Magic” type of season. Bet on normalization at your own risk.
The Mariners’ lineup might also not be a leading candidate in forcing pitcher regression. Julio Rodriguez (concussion) and Brendan Donovan (groin) remain on the IL, and this squad is simply struggling to push runs across home plate. For 2026 as a whole, Seattle ranks 26th in runs scored (381). Over the past two weeks, the team combines a .226 batting average with a massive 26.7% strikeout rate. It’s not what you want to see.
Mariners vs. Rays pick, best bet
For as much as I don’t really trust Nick Martinez’s 2.61 ERA — it’s a 2.61 ERA. Add in Castillo’s 2.72 ERA over his last seven appearances, and you have the makings of a pretty good pitchers’ duel. Not to mention the Mariners’ recent issues scoring runs.
Strong Lean: Nick Martinez Under 4.5 Strikeouts (-155)
Martinez is rocking a fourth percentile whiff rate (18.1%) and a sixth percentile strikeout rate (15.0%). As such, he’s gone under this prop in 13 of his 17 starts so far in 2026.