The Seattle Mariners (37-35) host the Boston Red Sox (38-37) on Wednesday, June 18, 2025. First pitch from T-Mobile Park is scheduled for 4:10 p.m. ET; the game will be broadcast on MLB Network.
This Red Sox-Mariners series is tied at a game apiece entering the Wednesday series finale, which features a potential pitchers' duel with Garrett Crochet and Luis Castillo.
Find my Red Sox vs Mariners prediction and moneyline pick for Wednesday below.
Boston Red Sox vs Seattle Mariners Prediction, Pick
- Red Sox vs Mariners pick: Red Sox Moneyline (play to -140)
My Red Sox vs Mariners best bet is the Red Sox moneyline. Make sure to find the best odds by checking our live MLB odds page.
Red Sox vs Mariners Odds, Lines
| Red Sox Odds | ||
|---|---|---|
| Run Line | Total | Moneyline |
-1.5 +148 | 6.5 -117o / -103u | -120 |
| Mariners Odds | ||
|---|---|---|
| Run Line | Total | Moneyline |
+1.5 -181 | 6.5 -117o / -103u | -102 |
Red Sox vs Mariners Projected Starting Pitchers
| LHP Garrett Crochet (BOS) | Stat | RHP Luis Castillo (SEA) |
|---|---|---|
| 6-4 | W-L | 4-4 |
| 2.7 | fWAR (FanGraphs) | 1.0 |
| 2.24/3.02 | ERA /xERA | 3.29/4.50 |
| 2.73/2.77 | FIP / xFIP | 3.88/4.24 |
| 1.03 | WHIP | 1.27 |
| 23.3% | K-BB% | 12.2% |
| 48.1% | GB% | 40% |
| 114 | Stuff+ | 97 |
| 96 | Location+ | 104 |
Red Sox vs Mariners Preview, Prediction
Red Sox Betting Preview
Amidst all the anger from Red Sox fans about the now-departed Rafael Devers, the fan base now has a new favorite — fireballing lefty Garrett Crochet.
Boston's ace, Crochet, pitched a dominant 8 1/3 innings with seven strikeouts against the Yankees. He was eyeing a shutout, then Aaron Judge took a 99 mph four-seamer 446 feet.
The best part about Crochet is he's a shoo-in to pitch six or seven innings — at least. He leads MLB with 96 1/3 innings, ranks eighth with a 2.24 ERA, and is second — behind Tarik Skubal with 117 strikeouts.
None of this is a fluke by Crochet. He has an elite 114 Stuff+, strikes out 10.93 batters per nine, and has a 2.73 FIP. Everything the hard-throwing lefty does is that of an elite pitcher. He's worth backing every time you can get a favorable price with him.
Boston ranks third in wRC+ (118) in June, and eight players not named Devers have a wRC+ better than 105.
Abraham Toro is probably hitting above his weight, but he has a 157 wRC+ this month, while Carlos Narvaez has a 152 and Trevor Story has a 128.
I'm still a believer in Boston's offense in the post-Devers era if it gets production from those three, plus the trio of youngsters in Roman Anthony, Marcelo Mayer and Kristian Campbell.
Mariners Betting Preview
Luis Castillo isn't on Crochet's level of dominance. He appears due for regression, boasting a strong 3.29 ERA but a 4.50 xERA and 3.88 FIP. The veteran right-hander has a career-worst 7.60 K/9 and a 2.95 BB/9, his worst mark since 2021.
Castillo's batted-ball data is also a cause for concern. He ranks in the 11th percentile in barrel rate, 19th in hard hit, and 30th in average exit velocity.
The Mariners' offense is much better than it was in the past few seasons, ranking 11th in MLB with 107 wRC+ in June. It helps to a legitimate MVP candidate in catcher Cal Raleigh, but it's JP Crawford and Dominic Canzone who lead Seattle in wRC+ this month.
The good news for Boston? Both Crawford and Canzone are lefties. Canzone is largely a platoon bat, while Crawford would prefer to face a right-hander.
Seattle has also punched out at a 23% clip through 15 games in June, including eight times to Lucas Giolito in Monday's loss to Boston.
In the first meeting versus Crochet, Seattle scored five runs in five innings, but it walked five batters. That was his season-high in walks, but the Mariners also punched out nine times. I can't picture the Mariners walking that much against Crochet this time.
Red Sox vs Mariners Prediction, Betting Analysis
The Red Sox are focusing on run prevention until Alex Bregman is back. But their offense can get to Castillo, even with the offense being less lethal with Devers gone.
I love backing Crochet here, as he's one of the best pitchers in MLB and there won't be many chances to take Boston in the -125 range with him.
Plus, the Red Sox back end of the bullpen is nothing to scoff at. They have Greg Weissert, Garrett Whitlock and Aroldis Chapman as options in the game's later innings.
If Crochet can provide six or seven strong innings, I have plenty of trust in any combination of those three to shut the door in Seattle.
Pick: Red Sox Moneyline (play to -140)
Moneyline
I like Boston here.
Run Line (Spread)
No run line play.
Over/Under
No total play.
Red Sox vs Mariners Betting Trends
Red Sox vs Mariners Viewing Info: Channel, Start Time, Streaming
| Location: | T-Mobile Park in Seattle, Wash. |
| Date: | Wednesday, June 18 |
| Time: | 4:10 p.m. ET |
| TV / Streaming Options: | ROOTNW, NESN, MLB Network |
