5 Mariners to blame for regifting the Blue Jays home-field advantage in the ALCS

The Mariners went from being in complete command to having to play catch-up with a trip to the World Series on the line.
Oct 16, 2025; Seattle, Washington, USA; Seattle Mariners pitcher Luis Castillo (58) walks off the mound after being relieved against the Toronto Blue Jays in the third inning during game four of the ALCS round for the 2025 MLB playoffs at T-Mobile Park. Mandatory Credit: Stephen Brashear-Imagn Images
Oct 16, 2025; Seattle, Washington, USA; Seattle Mariners pitcher Luis Castillo (58) walks off the mound after being relieved against the Toronto Blue Jays in the third inning during game four of the ALCS round for the 2025 MLB playoffs at T-Mobile Park. Mandatory Credit: Stephen Brashear-Imagn Images | Stephen Brashear-Imagn Images

After stealing the first two games of the ALCS on the road, the Seattle Mariners looked poised to win their first-ever AL pennant. All they had to do was win two of the next five games, three of which would be played at T-Mobile Park in Seattle. Julio Rodriguez's first-inning home run in Game 3 gave Mariners fans reason to believe this series might not even get sent back to Toronto at all. Well, that couldn't have been further from the truth in hindsight.

The Mariners got shelled in Game 3, and lost in disappointing fashion in Game 4. They took an early lead against Max Scherzer on Thursday night, a pitcher not even on Toronto's ALDS roster, but the offense went cold after that, and the pitching imploded. The Jays won the game, and have evened the series at two games apiece.

Now, the series is guaranteed to go back to Toronto, and the Mariners will have to win at least one more game at Rogers Centre to advance to the World Series. No, the series is far from over, but all of the momentum they picked up in Toronto has completely flipped to the other side. The Jays now sit in the driver's seat. These five players deserve most of the blame for this unfortunate situation that the Mariners now find themselves in.

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5) 1B Josh Naylor

Yes, this might be seen as a strange pick. Naylor had a three-hit game in Game 2 of this series and had a huge day, including a home run, in Game 4, but his base-running blunder is what Mariners fans will remember from his performance in the home games during this ALCS thus far.

The Mariners were down 5-1 in the bottom of the sixth but were finally rallying. Naylor had just drawn a walk against reliever Mason Fluharty, putting two runners on with nobody out. Eugenio Suarez continued the inning by lining a base hit to right, plating Jorge Polanco. It was safe to assume the Mariners were about to send the tying run to bat, but Naylor had other ideas. He inexplicably tried to go first to third on Suarez's hit, and was thrown out by a substantial margin by Addison Barger in right field.

Sure, it took a good throw to get him, but the hit went to shallow right field, Naylor is not exactly fleet of foot and Barger has one of the strongest arms in the game. Would the Mariners have tied the game or even cut further into Toronto's lead? There's no way of knowing, but Naylor making the third out at third base is a Little League mistake teams can ill-afford to make in the postseason.

Maybe I am being too harsh, because Naylor did have a good game when removing that blunder, but that mistake in that spot is impossible to overlook. The rally was killed right there, and the Jays immediately responded by scoring three runs in the next two innings, just about putting the game out of reach.

4) RP Gabe Speier

Speier, the Mariners' best left-handed reliever, was brought into Game 4 earlier than anticipated. Luis Castillo struggled mightily in the third and was pulled with the bases loaded and one out. Sure, it was a tough spot for Speier to be put into, but with Daulton Varsho, a left-handed hitter who had a .701 OPS against southpaws in the regular season, coming up, there was a path out of the inning. Unfortunately, Speier walked Varsho after getting ahead in the count 1-2, turning a 2-1 game into a two-run deficit.

He was able to strike out the next two batters he'd face, so had that walk been the only blemish on Speier's final line, I probably would've excused him. Unfortunately, he was brought back out for the fourth inning, and that did not pay off. Isiah Kiner-Falefa began the inning with a bloop hit, and two batters later, George Springer drove him in with an RBI double.

A wild pitch from Matt Brash allowed Springer to score, so that was a bit unlucky on Speier's end, but even without that extra run the southpaw just didn't get the job done. He was unable to get out of Castillo's jam unscathed in the third, and then allowed two runs of his own in the fourth. Not what you want from a key reliever.

3) OF Randy Arozarena

Arozarena has a reputation for being an outstanding postseason performer, but that hasn't been the case this season for Seattle. He hits in a prime spot, leading off ahead of Cal Raleigh and Julio Rodriguez, but he hasn't done much with the opportunity he's been given, particularly in the ALCS. He had a pretty good Game 3, reaching base twice while scoring two runs and driving in a run, but Game 4 is the game we need to highlight here.

Arozarena went 0-for-4 with two strikeouts, one of which was beyond inexcusable. Dominic Canzone led off the bottom of the fifth with a single, but even after getting the next two batters out, John Schneider wanted to remove Max Scherzer from the game. Scherzer, in true Scherzer fashion, barked at him and wound up staying in to face Arozarena for a third time. Had he reached against a pitcher the Blue Jays wanted to pull, Seattle would've had two men on with Raleigh up next, giving themselves a prime opportunity to cut into their deficit.

Unfortunately, Arozarena had one of the worst at-bats of the night by any player. He stared at each of the first three pitches, two of which were fastballs for strikes, then decided to swing at a slider that wasn't anywhere near the zone.

He wasn't the only one who had poor at-bats in this game, but it felt like this strikeout was a turning point in the game. Arozarena could not have had much of a worse at-bat in an important spot.

2) SP Luis Castillo

Castillo had an up-and-down regular season, but he finished strong and didn't allow a single run in each of his first two postseason appearances, one of which came in relief to send Seattle to the ALCS. All he had to do in Game 4 was outduel Scherzer, a 41-year-old whose best days were so clearly behind him. Scherzer was better than anticipated, but Castillo really didn't live up to his end of the bargain either.

Castillo was handed a 1-0 second-inning lead on Naylor's home run, but not only did he give that lead up, he failed to even get out of the third inning. That third frame began with Kiner-Falefa, a player who likely wouldn't have started had Anthony Santander been healthy, ripping a double to left field. The next batter, one of the weakest-hitting position players in the sport in Andres Gimenez, drilled a two-run homer to right, giving Toronto a lead it would not relinquish.

It's one thing to let Vladimir Guerrero Jr. beat you, but it's another to let Kiner-Falefa and Gimenez beat you. After allowing three of the next four batters to reach, Castillo was pulled. He wound up allowing three runs on five hits in just 2.1 innings of work. This was not what the Mariners wanted to see, especially after dropping Game 3 and getting an early lead in Game 4.

1) SP George Kirby

Castillo was bad, but Kirby was worse. The Mariners began Game 3 of this series with all of the momentum on their side, and that was only emphasized when Julio Rodriguez hit a two-run shot in the first inning against Shane Bieber. The Mariners had a 2-0 series lead and had a 2-0 lead in Game 3. It truly did feel like the series was in hand, especially when considering how well Kirby pitched in each of his two ALDS starts.

Unfortunately, after cruising through the first two innings, the third frame was eerily similar to the inning Castillo had. Ernie Clement led off with a double, and Gimenez, the weakest link, drilled a two-run shot to tie the game. What happened after that home run is even more frustrating for Mariners fans.

Kirby allowed three of the next five batters to reach, the last of which, Alejandro Kirk, drew a rare walk against the right-hander, loading the bases for Daulton Varsho. A wild pitch from the notoriously command-centric Kirby allowed the go-ahead run to score, and then a ringing two-run double plated two more runs. What was a 2-0 lead for the Mariners was a 5-2 deficit by the time the top of the third ended.

As if that wasn't bad enough, Dan Wilson stuck with his All-Star starter, and Kirby allowed home runs to George Springer and Vladimir Guerrero Jr. in consecutive innings, making it 7-2 Jays. Another run was tacked on after he was pulled in the fifth, making it 8-2. Kirby allowed eight runs on eight hits in four innings of work overall. His blowup tilted momentum in the Jays' way, and so far, Toronto has not looked back since.