Mariners Schedule 2025: ALCS Dates, Opponent Analysis, and World Series Predictions

The Seattle Mariners are set for their first ALCS appearance since 2001 after clinching the AL West title, with baseball’s spotlight now shining on their championship potential. Home-field advantage at T-Mobile Park gives Seattle a critical edge against either the Yankees or Blue Jays, setting the stage for an epic October showdown.

With Luis Castillo leading a dominant rotation and Cal Raleigh’s historic 60-homer season, the Mariners have the tools to overcome any AL opponent. As the baseball world debates potential World Series matchups, Seattle’s rested roster appears perfectly positioned for a deep postseason run.

Mariners Schedule 2025: ALCS Dates and Playoff Roadmap

The Seattle Mariners have scripted a historic 2025 season, securing their first AL West title since 2001 and earning a coveted bye through the Wild Card round. Their ALCS schedule is set to commence on October 15th at T-Mobile Park, where they’ve dominated opponents with a remarkable .720 home winning percentage. Having swept the Cleveland Guardians in the ALDS, the Mariners enter the Championship Series with their rotation perfectly aligned.

Manager Scott Servais has strategically rested key players including Julio Rodríguez and J.P. Crawford during the four-day break between series. The pitching staff features Luis Castillo, Logan Gilbert and George Kirby ready in sequence, presenting opponents with one of baseball’s most formidable rotations. Seattle’s path through the playoffs remains entirely in their home park thanks to securing the American League’s best regular-season record.

• ALCS Game 1: October 15th – T-Mobile Park
• Potential Game 7: October 23rd – T-Mobile Park
• Rest advantage: 4 days compared to opponent’s 2

The Mariners bullpen trio of Andrés Muñoz, Matt Brash and Paul Sewald enters the ALCS with a combined 1.89 ERA since September 1st. This deep relief corps gives Seattle crucial flexibility in high-leverage situations.

What makes Seattle’s schedule advantage so critical is their home/road split. At T-Mobile Park, they score nearly two more runs per game while allowing fewer than half as many home runs compared to road games.

Projected ALCS Rotation

• Game 1: Luis Castillo (2.78 ERA, 212 Ks)
• Game 2: Logan Gilbert (3.05 ERA, 194 Ks)
• Game 3: George Kirby (2.91 ERA, 187 Ks)

ALCS Opponent Breakdown: Yankees vs. Blue Jays

The Mariners await the winner of the thrilling ALCS between the Toronto Blue Jays and New York Yankees, two teams presenting distinctly different challenges. Toronto’s balanced offensive attack led by Vladimir Guerrero Jr. and Bo Bichette contrasts sharply with New York’s power-heavy lineup featuring Aaron Judge and Juan Soto.

Statistical analysis reveals surprising advantages for Seattle against both potential opponents:

The Yankees’ right-handed heavy lineup has particularly struggled against Seattle’s power arms, hitting just .212 with runners in scoring position during regular season matchups. Meanwhile, Toronto’s plate discipline presents different challenges, having drawn the most walks while striking out least in the AL.

While Toronto’s offense looks scarier on paper, Seattle’s pitching depth matches up better against the Yankees. New York hasn’t solved Castillo’s changeup or Kirby’s splitter all season – that’s a psychological edge heading into Game 1.

Key Players Comparison

• Toronto: Guerrero Jr. (.314 BA, 42 HR), Bichette (.298 BA)
• New York: Judge (54 HR), Soto (.423 OBP)

The Cal Raleigh Factor: Mariners’ Secret Weapon

Catcher Cal Raleigh has emerged as the heartbeat of Seattle’s historic season, joining Johnny Bench as the only catchers ever to hit 60 home runs in a season. His 60 HRs and 147 RBIs both led the majors, while his improved game-calling has been instrumental in developing Seattle’s young staff.

Raleigh’s switch-hitting ability presents matchup nightmares for opposing managers:

• Vs RHP: .278 BA, 38 HR
• Vs LHP: .265 BA, 22 HR
• Clutch ABs: .342 BA with RISP

The ALCS stage could serve as Raleigh’s national coming-out party before impending free agency. His 12 go-ahead hits in the eighth inning or later demonstrate remarkable poise in high-leverage situations.

Modern baseball hasn’t seen a catcher dominate offensively while handling a pitching staff this well since prime Mike Piazza. Raleigh’s framing metrics improved 20% this year – he’s become the complete package behind the plate.

Historic Catcher Seasons

World Series Projections: Potential Matchups Analyzed

Should Seattle advance past the ALCS, baseball’s ultimate stage could produce several compelling World Series narratives. A matchup with the NLCS-winning Los Angeles Dodgers would feature baseball’s two deepest rotations, while facing Milwaukee would pit Seattle’s power arms against the Brewers’ contact-heavy approach.

Historical context adds layers to potential Fall Classic matchups:

• Mariners vs Dodgers: First postseason meeting
• Mariners vs Brewers: Would be Seattle’s first WS appearance
• Mariners vs Phillies: Rematch of 2024 NLWC showdown

The Mariners’ road ERA of 3.89 could become concerning against NL powerhouses, particularly when facing lineups stacked with left-handed power in more hitter-friendly parks. However, Seattle’s bullpen depth gives them unique flexibility in potential National League ballparks without the DH.

Don’t sleep on Seattle’s ability to handle NL rules. Their bench bats like Dylan Moore crush lefties (.892 OPS), while defensive replacements late in games could prove crucial without the DH.

Rotation Matchup Comparison

X-Factors That Could Decide Seattle’s Playoff Fate

Beyond the established stars, several under-the-radar factors could determine whether Seattle’s magical season culminates in a World Series championship. Rookie outfielder Jonatan Clase’s baserunning prowess (42 steals) provides crucial late-game weaponry, while veteran lefty Tyler Anderson’s renaissance (3.41 ERA) offers rotation stability.

Key peripherals suggest hidden advantages:

• Defensive Runs Saved: +48 (2nd MLB)
• Baserunning Runs: +22 (1st AL)
• Bullpen Inherited Runners Stranded: 78% (3rd MLB)

The Mariners’ preparation during their extended break bears monitoring. Historical data shows teams with 5+ days rest before the ALCS:

Seattle’s baseball ops team excels at exploiting small edges. Watch how they deploy Ty France’s elite pitch-framing skills late in games when pinch-running for Raleigh – those 20 extra strikes per series add up.

Critical Matchup Advantages

• Julio Rodríguez vs high fastballs: MLB-best .412 BA
• Mariners catchers’ pop time: 1.87s (1st AL)
• Bullpen fastball velocity: 98.4 mph avg (1st MLB)