Red Sox vs Mariners Picks and Predictions: September 15

Boston and Seattle are both right in the thick of the AL Wild Care race, and desperate to pick up Ws as they face off today. But the matchup at the plate strongly favors one side — find out which with our Red Sox vs Mariners picks.

Last Updated: Sep 15, 2021 10:27 AM ET Read Time: 4 min
Tanner Houck MLB Boston Red Sox
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The Boston Red Sox are currently tied with the Yankees and Blue Jays for two AL Wild Card spots while the Mariners are just three games out of both wild card spots. 

With just a little over a half of a month to go in the regular season, Boston and Seattle need to win as many games as possible — who will prevail in today’s rubber match?

Red Sox vs Mariners game info

Location: Stadium, City, State/Province
Date: Wednesday, September 15, 2021
Time: 4:10 p.m. ET

Red Sox vs Mariners odds

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Red Sox vs Mariners betting preview

Starting pitchers

Tanner Houck (0-4, 3.54 ERA): Tanner Houck has yet to record a win this season but still has an ERA of 3.54. It would be nice to see Houck go longer in games, as he hasn’t completed six innings at all this season. Still, Houck gives the Red Sox a chance to win every night he’s out there by allowing three earned runs or less in every start this season. 

Marco Gonzales (8-5, 3.95 ERA): The left-handed pitcher has struggled a lot this season despite an 8-5 record. Gonzales put together a very solid August but had a 5.48 ERA prior to that. Once August ended, Gonzales had a brutal outing against the Diamondbacks, allowing five runs on eight hits in five innings. His next outing against them was much better but he still allowed three runs.  


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Key injuries

Red Sox: Jonathan Arauz SS (Out), Christian Arroyo (Out), Matt Barnes RP (Probable), Jarren Duran OF (Out), Yairo Munoz OF (Out), Chris Sale SP (Out), Danny Santana OF (Out) Phillips Valdez RP (Out)
Mariners: Sam Haggerty OF (Out), Kyle Lewis Of (Out), Shed Long Jr. OF (Out)
Find our latest MLB injury reports.

Betting trend to know

Mariners are 1-4 in their last 5 games vs. a right-handed starter. Find more MLB betting trends for Red Sox vs. Mariners.

Moneyline pick

The Seattle Mariners haven’t exactly been lights out against right-handed pitching recently. While the projected lineup limits ground balls, the Mariners only have a wOBA of .300 with nearly 23 percent strikeouts against righties. 

Tanner Houck has been electric this season, posting a 3.79 xFIP along with 28 percent strikeouts. He’s inducing ground balls 46.8 percent of the time and allowing just over 20 percent line drives, which is actually above the average for a starting pitcher. 

Marco Gonzales will be on the mound for the Mariners, and he’s got a 5.53 xFIP in the last 30 days along with just 17.5 percent strikeouts. Gonzales struggles to induce ground balls and allows over 22 percent of line drives in the last 30 days. He’s been bad against righties, point-blank, with a .355 wOBA and .275 ISO in 333 plate appearances against righties. 

Meanwhile, the Red Sox offense has a little more juice to their bats against lefties. Despite an ISO of .145, the Red Sox lineup is hitting ground balls just 31.9 percent of the time and 31.8 percent of line drives. 

Basically, the lineup is hitting as many line drives as they are hitting ground balls. Against Gonzales, that all matches up to favor the Red Sox in this bout. 

Expect Houck to pitch a gem and the Red Sox to score enough runs to get the win. This could be Houck’s first win of the year. 

PREDICTION: Boston (-120)

Over/Under pick

The Red Sox will score runs in the first five innings against Gonzales. Boston has a career 1.361 OPS for the active roster against Gonzales, going 20-for-45 against him. 

In the first five innings, the line for the Red Sox is Over 2 as a team total. This would mean the Red Sox would need three to cash the ticket, but if they score just two, the bet would void and you’d get your money back. 

It’s hard to pick an Over/Under bet when you think one team might score plenty of runs and the other team won’t. Therefore, we’ll just roll with the first-five team total for the Red Sox, who are coming off an eight-run outing last night. 

PREDICTION: Red Sox Over 2 F5 (-130)

Red Sox vs Mariners betting card

  • Boston (-120)
  • Red Sox Over 2 F5 (-130)

Picks made on 9/15/2021 at 9:30 a.m. ET

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