Seattle Mariners vs Boston Red Sox Prediction & Picks - MLB

USA - MLB

Seattle Mariners
6/21/26 16:10
Boston Red Sox

Prediction:

 

Boston Red Sox ML

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 by Matt Lowrimore | in MLB Picks

A full 15-game MLB slate is scheduled for Sunday, which will include an American League matchup between the Seattle Mariners and the Boston Red Sox. Let’s take a look at the match statistics and predictions for this game between the Mariners and the Red Sox.

Boston enters this game well under .500 and is currently in last place in the American League East division. While the Red Sox have continued to struggle as of late, they are set to start Payton Tolle, who has been one of their better starting pitchers this season. In fact, Tolle has an ERA of 2.93, which is tied for the best of the team. He has also pitched well on the road this season, suggesting this trend could continue in the series finale.

As for Seattle, they enter this game about .500 on the season. The Mariners are to start Logan Gilbert in the series finale, who has a record of 5-4 on the season and an ERA of 3.43. However, Gilbert has been poor at home this season, further casting doubt on a Mariners’ win.

Seattle Mariners vs Boston Red Sox Form

Table

Teams Pts P W L
14 Seattle Mariners
0.506 77 39 38
27 Boston Red Sox
0.411 73 30 43

Seattle Mariners and Boston Red Sox Latest Matches

Seattle Mariners
Seattle Mariners Latest matches
L L W L W L
Victories

2/6 (33%)

Defeats

4/6 (67%)

Jun 19, 2026 - MLB

Seattle Mariners
2 :  6
Boston Red Sox

Jun 18, 2026 - MLB

Seattle Mariners
3 :  0
Baltimore Orioles

Jun 17, 2026 - MLB

Seattle Mariners
3 :  5
Baltimore Orioles

Jun 16, 2026 - MLB

Seattle Mariners
3 :  1
Baltimore Orioles

Jun 14, 2026 - MLB

Washington Nationals
10 :  1
Seattle Mariners

Jun 13, 2026 - MLB

Washington Nationals
8 :  3
Seattle Mariners
W L W L W L
Victories

3/6 (50%)

Defeats

3/6 (50%)

Jun 19, 2026 - MLB

Seattle Mariners
2 :  6
Boston Red Sox

Jun 18, 2026 - MLB

Seattle Mariners
3 :  0
Baltimore Orioles

Jun 17, 2026 - MLB

Seattle Mariners
3 :  5
Baltimore Orioles

Jun 16, 2026 - MLB

Seattle Mariners
3 :  1
Baltimore Orioles

Jun 3, 2026 - MLB

Seattle Mariners
1 :  7
New York Mets

Jun 2, 2026 - MLB

Seattle Mariners
8 :  3
New York Mets
W L L W L L
Victories

2/6 (33%)

Defeats

4/6 (67%)

Jun 14, 2026 - MLB

Washington Nationals
10 :  1
Seattle Mariners

Jun 13, 2026 - MLB

Washington Nationals
8 :  3
Seattle Mariners

Jun 12, 2026 - MLB

Washington Nationals
2 :  10
Seattle Mariners

Jun 11, 2026 - MLB

Baltimore Orioles
7 :  5
Seattle Mariners

Jun 10, 2026 - MLB

Baltimore Orioles
7 :  2
Seattle Mariners

Jun 9, 2026 - MLB

Baltimore Orioles
5 :  6
Seattle Mariners
Boston Red Sox
Boston Red Sox Latest matches
W L L L L W
Victories

2/6 (33%)

Defeats

4/6 (67%)

Jun 19, 2026 - MLB

Seattle Mariners
2 :  6
Boston Red Sox

Jun 18, 2026 - MLB

Boston Red Sox
3 :  4
Toronto Blue Jays

Jun 17, 2026 - MLB

Boston Red Sox
0 :  3
Toronto Blue Jays

Jun 16, 2026 - MLB

Boston Red Sox
1 :  6
Toronto Blue Jays

Jun 14, 2026 - MLB

Boston Red Sox
4 :  6
Texas Rangers

Jun 13, 2026 - MLB

Boston Red Sox
6 :  3
Texas Rangers
W W L L L L
Victories

2/6 (33%)

Defeats

4/6 (67%)

Jun 18, 2026 - MLB

Boston Red Sox
3 :  4
Toronto Blue Jays

Jun 17, 2026 - MLB

Boston Red Sox
0 :  3
Toronto Blue Jays

Jun 16, 2026 - MLB

Boston Red Sox
1 :  6
Toronto Blue Jays

Jun 14, 2026 - MLB

Boston Red Sox
4 :  6
Texas Rangers

Jun 13, 2026 - MLB

Boston Red Sox
6 :  3
Texas Rangers

Jun 12, 2026 - MLB

Boston Red Sox
10 :  1
Texas Rangers
W L L L L W
Victories

2/6 (33%)

Defeats

4/6 (67%)

Jun 19, 2026 - MLB

Seattle Mariners
2 :  6
Boston Red Sox

Jun 10, 2026 - MLB

Tampa Bay Rays
7 :  5
Boston Red Sox

Jun 9, 2026 - MLB

Tampa Bay Rays
4 :  3
Boston Red Sox

Jun 8, 2026 - MLB

Tampa Bay Rays
3 :  1
Boston Red Sox

Jun 7, 2026 - MLB

New York Yankees
6 :  1
Boston Red Sox

Jun 5, 2026 - MLB

New York Yankees
3 :  5
Boston Red Sox

Seattle Mariners against Boston Red Sox : Head to Head (H2H)

Seattle Mariners

50 %

Boston Red Sox

50 %

Jun 19, 2026 - MLB

Seattle Mariners
2 :  6
Boston Red Sox

Jun 18, 2025 - MLB

Seattle Mariners
1 :  3
Boston Red Sox

Jun 17, 2025 - MLB

Seattle Mariners
8 :  0
Boston Red Sox

Jun 16, 2025 - MLB

Seattle Mariners
0 :  2
Boston Red Sox

Apr 24, 2025 - MLB

Boston Red Sox
3 :  4
Seattle Mariners

Apr 23, 2025 - MLB

Boston Red Sox
5 :  8
Seattle Mariners

Seattle Mariners - Boston Red Sox Key Points

  1. Payton Tolle has an ERA of 2.93 this season
  2. Payton Tolle has an ERA of 3.16 on the road this season
  3. Logan Gilbert has an ERA of 3.43 this season
  4. Logan Gilbert has an ERA of 5.02 at home this season

Our Seattle Mariners vs Boston Red Sox Prediction

The Mariners are the clear favorite; however, the Red Sox look to be the best betting option. There is no question that Boston has been underwhelming this season, but having Tolle on the mound gives them a great chance to win. Tolle has made four away starts this season, having allowed 11 runs (nine earned) over 25.2 innings. Gilbert, on the other hand, has made nine starts this season and has allowed 29 earned runs over 52.0 innings.

Boston’s offense has by no means been consistent this season, but given Gilbert’s struggles when pitching at home, our Seattle Mariners vs Boston Red Sox prediction is: Boston Red Sox ML.

Prediction:

 

Boston Red Sox ML

+119
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Seattle Mariners vs Boston Red Sox Picks