The Seattle Mariners host the Boston Red Sox on June 19, 2026. First pitch from T-Mobile Park is scheduled for 10:10 p.m. EDT. The game will be broadcast on NESN.
The Red Sox are favored by -102 on the moneyline and by -1.5 on the run line. The Mariners are -116 on the moneyline and +1.5 on the run line. The total is set at 6.5 runs.
Find my MLB picks and Red Sox vs Mariners prediction below, as well as probable pitchers, weather report, and more.
Red Sox vs Mariners Prediction
- Red Sox vs Mariners Pick: Red Sox ML (-102, FanDuel | Play to -115)
My Red Sox vs Mariners best bet is on Boston to win. Make sure to find the best odds by checking our live MLB odds page.
Red Sox vs Mariners Odds
| Red Sox Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
-1.5 +168 | 6.5 -120o / -102u | -102 |
| Mariners Odds | ||
|---|---|---|
| Spread | Total | Moneyline |
+1.5 -205 | 6.5 -120o / -102u | -116 |
- Red Sox vs Mariners moneyline: Red Sox -102, Mariners -116
- Red Sox vs Mariners over/under: 6.5 (-120o / -102u)
- Red Sox vs Mariners spread: Red Sox -1.5 (+168), Mariners +1.5 (-205)
Red Sox vs Mariners Polymarket MLB Odds
Red Sox vs Mariners Probable Pitchers
| Ranger Suarez | Stat | Bryce Miller |
|---|---|---|
| 2-3 | W-L | 3-0 |
| 2.2 | fWAR (FanGraphs) | 0.9 |
| 3.21 / 3.45 | ERA / xERA | 1..54 / 2.35 |
| 2.82 / 3.55 | FIP / xFIP | 2.95 / 3.00 |
| 17.1 | K-BB% | 24.8 |
| 38 | GB% | 40.2 |
| .302 | BABIP | .200 |
| 95 | Stuff+ | 111 |
| 104 | Location+ | 110 |
Red Sox vs Mariners MLB Betting Preview
Boston Red Sox Betting Preview
The Red Sox have not won since Ranger Suarez pitched on June 13, and now, six days later, they'll be looking to Suarez to snap a four-game slide. The lefty struck out seven Rangers over five innings of two-run ball, and after a rough end to May, his ERA for the month stands at 2.38.
Suarez, who has been as consistent as they come over the last few seasons, has taken on a different form since teaming up with Andrew Bailey in Boston. The sinker-baller has moved away from his changeup, which posted good numbers last season, in favor of more fastballs. He's hardly offering anything off-speed, and it's led to a drastic drop in ground balls.
After operating as a heavy ground-ball pitcher for his entire career, Suarez is yielding a 60.6% air-contact rate, which would be the highest mark of his career by five percentage points, more than eight points higher than his career average and five points above the league average. Most of that contact has actually come in the form of line drives, and while they haven't been struck particularly hard, with a solid average exit velocity, Suarez is now operating with a poor 20.7% Pull Air%.
Suarez has maintained a solid 3.41 Expected ERA, but much of that has to do with his continued growth in the strikeout department and another excellent walk rate at 7.3%. He's allowed a .241 Expected Batting Average — 15 points higher than last season — but his Expected Slugging is 55 points better than league average for a second straight year.
Seattle Mariners Betting Preview
The Mariners are hemorrhaging, having lost five of their last seven games as we head into the meat of the season. They're set to deploy Luis Castillo as a bulk reliever behind Bryce Miller on Friday, which will be the first of three piggyback appearances for Castillo heading into the break, and that's going to create an interesting wrinkle here.
Miller, for all the bad things I've said about him in the past, has had a nice season since debuting in May. He's pitched to a 1.54 ERA across 35 innings, while posting a 28.8% strikeout rate and a 4% walk rate that have to be considered elite. Still, we have to pump the brakes a bit, just like Seattle is doing.
The young righty may sport plenty of excellent predictive metrics, but he's faced the Astros, White Sox, Athletics, Tigers and Nationals. That's not exactly a murderers' row, and since Miller's season debut, both Houston and Detroit rank among the bottom six in wRC+. It's important to keep his confidence high after a brutal 2025, and he'll likely work through the order once here, perhaps a bit more.
Castillo is the bigger project. Coming off a 4.67 ERA in May, he's allowed six runs (three earned) in 11 1/3 innings in June, and his strikeout rate continues to be abysmal. The good news is that he's been solid underneath the hood, posting a .207 xBA and a .347 xSLG in June. The bad news is that those numbers came against Detroit and Washington.
The righty has always allowed plenty of hard-hit balls in the air, but with a sustained drop in strikeouts and a slight increase in walks, Castillo has done everything to earn his 5.00 ERA. The good news, I suppose, is that his xBA is a bigger issue than his xSLG, but with a 22.3% Pull Air% — almost seven points worse than average — it's hard to get excited.
Red Sox vs Mariners Pick, Betting Analysis
The Red Sox may be slumping hard at the plate, but this offense should get a boost in a favorable matchup with Castillo. Not only does Boston rank fifth in OPS against fly-ball pitchers, but it has also had very little issue making contact.
Considering its strikeout rate has remained under 22%, along with poor walk numbers and a respectable .171 Isolated Power over the last two weeks, we can safely say there will be plenty of swings and plenty of potential for power. There's little to suggest Castillo is breaking free from the issues that have plagued him, and it also doesn't seem likely that Miller will work very deep into this game.
On the other hand, Suarez should be in a good spot against the fourth-worst offense in baseball against left-handed pitching by wRC+. Seattle also ranks fourth worst in xwOBA against all fastballs thrown by lefties. Considering so much of the contact against Suarez comes through the air, the ballpark should work in his favor and help lift both him and the Red Sox to a much-needed win.
Pick: Red Sox ML (-102, FanDuel | Play to -115)
