MLB Playoffs: First look at ALCS between Mariners and Blue Jays
The top two seeds in the American League meet for a chance to play in the Fall Classic. Here’s a first look at how Seattle and Toronto compare.
The 2025 American League Championship Series matchup is now defined!
Starting Sunday in Toronto, the No. 2-seeded Seattle Mariners and No. 1-seeded Toronto Blue Jays will square off with a World Series berth on the line.
Seattle beat the Detroit Tigers in a thrilling Game 5 of the American League Division Series on Friday night, two days after Toronto beat the American League East rival New York Yankees to reach the American League Championship Series.
What has stood out about both teams so far? What does each one need to secure their ticket to the Fall Classic? And who are the X factors in each squad? Our AM850 MLB experts break it all down.
Note: Matchup probabilities come from the Doolittle formula, which uses power ratings as a basis for 10,000 simulations to determine the most likely outcomes. Computer temperatures are based on Bill James’ formula to determine how “hot” or “cold” a computer is at any given time; the average is 72°.
Toronto Blue Jays vs. Seattle Mariners
At last! Fans of the 1977 expansion have been waiting for this League Championship Series (SCL) showdown since the early days of the Carter administration. The Blue Jays and the Mariners were born at the same time, but they had never faced each other in something so important. The M’s beat the Jays in a wild card round matchup in 2022, but this is different.
The two strongest division champions in the American League are competing to end long World Series droughts. Toronto hasn’t won the title in 31 years, and Seattle has never won it.
The great Willie Horton was one of the first players to play for both franchises. Although he is remembered more as a Tiger and has a statue outside Comerica Park, he should be allowed to throw the first pitch in Seattle and Toronto. –Bradford Doolittle
Level of concern for No. 1 seed Blue Jays: Correctly alert. Toronto has the better position and home-field advantage, but Seattle has been playing slightly better in the latter stages of the season, and the run differentials are about the same.
What’s really exciting is the star power on both teams and that the most notable figures have shined in October. Julio Rodríguez, Cal Raleigh and the powerful Vladimir Guerrero Jr. have been fundamental for the teams to have come this far.
Both teams have relied on the home run to score, achieving more than half of their runs with home runs. It’s a very close matchup that could be decided by Andrés Muñoz, Seattle’s advantage in the back of the bullpen.–Doolittle
Toronto Blue Jays
Odds of advancing: 55.1%
Equipment temperature: 36°
What was the highlight of the Blue Jays’ blowout victory over the Yankees in the American League Division Series?
Castle: The relentlessness of their lineup. Vladimir Guerrero Jr. shined from start to finish, but Toronto received contributions from virtually every player manager John Schneider put into play. Four players not named Guerrero had two hits in Game 1. Daulton Varsho had four extra-base hits and Ernie Clement went 3 for 4 in Game 2. Clement added four more hits in Game 3.
The Blue Jays were the toughest team to strike out during the regular season, recording more home runs than strikeouts in the first two games at Rogers Centre, where they have shined all season. Helping was the appearance of Vladdy Jr., the Playoff player, who went 9 for 17 with three home runs, including a monumental grand slam in Game 2.
Schoenfield: To Trey Yesavage’s absolutely dominant performance in Game 2, he made his fourth career start and held the Yankees hitless for 5⅓ innings, striking out 11. The Yankees had no chance against him. Except for the length of the opener (the Blue Jays took it out with a big lead), it was the most dominant postseason performance we’ve seen in a long time.
His overarm pitch creates an unusual look for hitters, and he’s throwing 95-96 mph with a slider and a dazzling splitter. It’s hard to believe that 19 players were selected ahead of him in the 2024 draft.
Why will it work (or not) against the Mariners in the American League Championship Series?
Castle: It will operate at the Rogers Center as it always has operated at the Rogers Center this season. The Blue Jays scored 431 runs at home during the regular season, third most in the majors. In the American League Division Series, they scored 23 in two games in Toronto. The Blue Jays dominate pitchers north of the border. The question is whether it will work in Seattle. T-Mobile Park is a tough place to hit. Mariners pitchers posted a 3.28 ERA at home this season. But the Blue Jays scored 21 runs in a three-game sweep against the Mariners in May. Maybe his trip offensive.
Schoenfield: Yes…if he throws strikes. He did it against the Yankees, allowing just one walk in his start, but in the minors, he walked 41 in 98 innings. The Mariners have a mix of patient hitters (Cal Raleigh, Randy Arozarena) and win-seeking hitters (Julio Rodríguez, Eugenio Suárez), but like the Yankees, the Mariners also miss a lot.
Who is the key player who can boost (or destroy) Toronto’s hopes of winning the World Series?
Castle: Trey Yesavage. Asking a rookie with four major league starts to continue dominating well into October is a lot, but the Blue Jays lack that elite ace. Yesavage has the potential to achieve this. Not only does he have a good enough repertoire, but he’s different enough to baffle even the most experienced hitters. His release point and arm angle are among the highest in baseball, making his fastball and splitter combination especially difficult to solve. Plus, there’s his slider, which often runs on the arm side instead of the usual glove side. Toronto has been careful with the 22-year-old right-hander. He hasn’t thrown more than 94 pitches in a game this season, which opened for him in Class A Low. Now, he’s on the sport’s biggest stage and could make the difference come October.
Schoenfield: Shane Bieber. Kevin Gausman and Yesavage looked great, but with a 6-1 lead in Game 3, Bieber was knocked out in the third inning. Given how poorly Toronto’s bullpen pitched after that, perhaps it was a quick hit, but it’s clear that the Blue Jays will need all three of these starters to pitch well, given that the bullpen didn’t score many shutouts against the Yankees. The Blue Jays’ ability to put the ball in play (they had the lowest strikeout rate in the majors) means they should keep scoring runs, so the question is whether they can score enough.
Seattle Mariners
Chances of advancing: 44.9%
Equipment temperature: 89°
What stood out most about the Mariners’ victory over the Tigers in the American League Division Series?
Gonzalez: The effectiveness of the starting rotation, which should come as no surprise. George Kirby, Luis Castillo, Logan Gilbert and Bryce Miller, at least before the fifth inning, pitched well in the Division Series. Bryan Woo, the Mariners’ top starter this season, is expected to return from a pectoral injury for the American League Championship Series, taking this rotation to the next level.
The Mariners feel very good about their back-end relievers and believe this is the deepest lineup they’ve fielded in this era. But this team still revolves around its starting pitching, a unit that dominated throughout 2024 and finally began to regain its form down the stretch of this season. Starters need to pitch six and seven innings consistently so manager Dan Wilson doesn’t have to turn to anyone other than Gabe Speier, Matt Brash and Andrés Muñoz late in games. That’s the formula.
Doolittle: The depth of Seattle’s lineup is truly impressive, even without a featured designated hitter. It’s impressive to see Eugenio Suárez batting sixth and JP Crawford batting ninth. It’s a group that hits for power, steals bases and strikes out at a much less problematic rate than the Mariners lineups we’re used to. Raleigh and Rodríguez make up a dynamic one-two lineup. The R&R guys.
Why will it work (or not) against the Blue Jays in the American League Championship Series?
Gonzalez: No team struck out less often than the Blue Jays this season. Only the Yankees and Dodgers finished with a higher OPS. And come the playoffs, Vladimir Guerrero Jr., Ernie Clement and Daulton Varsho hit a combined 1,000 in four Division Series games. This offense operates at a different level than the Tigers, and could count on the return of Bo Bichette for the next round.
Gilbert and Woo pitched quite well against the Blue Jays this season (five earned runs in 11 2/3 innings). Castillo and Miller (15 earned runs in 15 innings) did not. But these two teams haven’t met since May. The Mariners’ rotation is not the same as it was back then.
Doolittle: A deep lineup works against anyone, but there is one factor that works in Seattle’s favor. With the promotion of Trey Yesavage for Toronto, the Blue Jays have four key pitchers who can dominate with splitters, the breakout pitch of the 2025 postseason. (Yesavage, Kevin Gausman, Seranthony Domínguez and Jeff Hoffman are the four).
The Mariners were in the middle of the pack in hitting splitters during the season, but they had two hitters who crushed them. And they are the R&R guys: Raleigh had a 1.159 OPS against splitters and Rodríguez, 1.091.
Which player is the X factor that can make (or break) Seattle’s World Series hopes?
Gonzalez: Randy Arozarena. The Mariners moved Arozarena to the top of the lineup after acquiring Eugenio Suarez and Josh Naylor at the trade deadline, and Arozarena has struggled a lot ever since. He showed some flashes in the American League Division Series, but the Mariners need the “Randy of the Playoffs,” the one who took the reins during the 2020 postseason and became a sensation playing for the Mexican National Team in the 2023 World Baseball Classic. If he gets going ahead of Cal Raleigh and Julio Rodríguez, the Mariners’ offense will be fearsome
Doolittle: Matt Brash. Well, that’s not fair, since Brash is good, and I chose his name as the avatar for Seattle’s middle relief corps. If the Mariners roster has a weak point, it is the non-tight end of the bullpen. It’s not a bad group, but with a deep, productive lineup and a star closer in Muñoz, plus excellent starting pitching, it could very well be Brash, Eduard Bazardo, Gabe Speier and Carlos Vargas who determine whether the Mariners can finally play in a World Series.
