Red Sox vs. Mariners Prediction, Odds, Probable Pitchers and Prop Bets for Wednesday, June 18

Sean Treppedi | Jun 18, 2025

Garrett Crochet looks to take his strikeout momentum into T-Mobile Park on Wednesday. / Brad Penner-Imagn Images

Cal Raleigh kept the home run train moving on Tuesday with a grand slam to help bury the Red Sox 8-0 and snap their six-game heater. 

It was Raleigh’s 27th home run, which leads the big leagues. 

Walker Buehler was responsible for all eight earned runs until he was relieved in the fourth inning. Bryan Woo, on the other hand, struck out six and shut down the Red Sox to just one hit. 

Wednesday’s rubber match will feature Sox ace Garrett Crochet (6-4, 2.24 ERA) and Mariners righty vet Luis Castillo (4-4, 3.29 ERA). 

Let’s get into how we can wager the series finale. 

Red Sox vs. Mariners Odds, Run Line and Total

Odds via FanDuel Sportsbook

Run Line

• Red Sox -1.5 (+160)
• Mariners +1.5 (-190)

Moneyline

• Red Sox (-118)
• Mariners (+100)

Total

• Over 6.5 (-120)
• Under 6.5 (-1-1)

Red Sox vs. Mariners Probable Pitchers

• Red Sox: Garrett Crochet (6-4, 2.24 ERA)
• Mariners: Luis Castillo (4-4, 3.29 ERA)

Red Sox vs. Mariners How to Watch

• Date: Wednesday, June 18, 2025
• Time: 4:10 p.m. ET
• Venue: T-Mobile Park
• How to Watch (TV): ROOTNW, NESN
• Red Sox Record: 38-37
• Mariners Record: 37-35

Red Sox vs. Mariners Best MLB Prop Bet

•  Garrett Crochet Over 7.5 Strikeouts (-154 at FanDuel)

Is this worth taking the bait? Crochet struck out nine in five innings against the Mariners on April 24. The question is whether he can replicate that in T-Mobile Park, which is home to the single-most strikeouts over the last three seasons per Statcast. Seattle is in the game’s top-five strikeout teams and whiffs on pitches at an appalling 27.4% clip. Crochet should be licking his chops with his 10.9 K/9 rate and an exceptional 114 Stuff+ rating. He’s dismissed eight or more hitters in five of his last seven starts. So my answer to taking him at -154 is worth the go.

Red Sox vs. Mariners Prediction and Pick

Aside from the durability and quality of Crochet’s pitching in his first season with the Sox, Boston’s offense has stepped up in June, ranking third in wRC+ (118), with surprising contributions from Abraham Toro, Carlos Narvaez, and Trevor Story. Perhaps Red Sox Chief Baseball Officer Craig Breslow isn’t bluffing: Even without Devers, the Sox offense remains formidable — especially against Luis Castillo, whose 3.29 ERA hides concerning signs like a 4.50 xERA and declining strikeout and walk rates. 

The Red Sox also have a trustworthy bullpen trio in Weissert, Whitlock, and Chapman to close out games behind Crochet. While Seattle's offense has improved, key contributors like JP Crawford and Dominic Canzone are lefties, making them less dangerous against the southpaw ace. Crochet tore it up in his last start despite walking five, but I think it's unlikely Seattle will draw that many free passes again.

Pick: Red Sox (-118 at FanDuel)

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