Toronto Blue Jays vs Seattle Mariners Game 5 Prediction – 10/17/2025

The Toronto Blue Jays and Seattle Mariners will face off in Game 5 of the American League Championship Series on Friday night. The Mariners took the first two games of this series in Toronto and the Blue Jays have returned the favor by winning the last two games in Seattle. Before the action begins in this contest from the Pacific Northwest, you can find my Blue Jays vs Mariners Game 5 prediction below.

Our Blue Jays vs Mariners Game 5 Pick

• Pick: Over 7
• Confidence: ★★★☆☆

Game Snapshot

• Matchup: Toronto Blue Jays vs Seattle Mariners
• Date & Time: Friday, October 17, 2025, 6:08 p.m. ET
• Starting Pitchers: Kevin Gausman (TOR) vs Bryce Miller (SEA)
• Stadium: T-Mobile Park, Seattle, WA
• Broadcast: FS1

Key Storylines

Pitching matchup

Seattle will hand the ball to Bryce Miller in this pivotal Game 5. Miller started Game 1 and has posted a 2.61 ERA in his two postseason starts so far. All-Star Bryan Woo will be held in reserve for bullpen duty after missing time due to injury.

Toronto will go with Kevin Gausman, who is making his third postseason appearance. He has thrown 11.1 innings this postseason, allowed three earned runs, and struck out eight. The starting pitching matchup is very even going into this huge matchup, where the winner will be one victory away from the World Series.

Key Players

• Vladimir Guerrero Jr.: Guerrero leads all Blue Jays hitters in power numbers this postseason and has been a consistent threat in October.
• Andrés Giménez: Giménez broke out in Game 4, going deep and driving in four runs. His production from the bottom half of the order has been a boost for the Blue Jays.
• Julio Rodríguez & Cal Raleigh: Seattle’s offense relies heavily on Rodríguez’s bat and Raleigh’s power. Raleigh has already launched a homer in this series, and Rodríguez continues to be the heartbeat of Seattle’s lineup.

Injuries will matter in this game as well. Toronto has removed outfielder Anthony Santander from its ALCS roster due to back issues. He won’t return even if Toronto advances. Joey Loperfido replaces him. Seattle will have Woo available out of the bullpen but he has not pitched in a while due to injury.

Best Player Props

Betting Trends & H2H

• Toronto leads the season series 6-4 against the Mariners between the regular season and postseason.
• The road team has won all four games in this series so far.
• The road team has won nine straight games played between these teams dating back to the regular season.
• Three straight games in this series have gone over their totals.

Blue Jays vs Mariners Game 5 Model Projection

Score Projection: Toronto 5 – Seattle 4

Win Probability: Toronto 54%, Seattle 46%

Final Thoughts

I see this being a closer game than we’ve seen in recent games of this series. But I think that the best bet here is on the game going over the total. Both of these offenses have been just mashing in recent games and we should see at least one of them put up a big number again here to extend the run of overs in this series to four games in a row.

Jay Sanin

Jay Sanin is the GM and Head of Sports at ATS.io. He has been writing about sports gambling since 2013, handicapping tens of thousands of sporting events. He plays sides and totals aggressively across most sports and is more selective in player prop markets. He does his own modeling across most sports, and his family is jealous of how much time he spends on his precious spreadsheets.