Cristopher Sánchez and 3 other breakout pitchers who will make or break the 2025 MLB playoffs

The Philadelphia Phillies have officially clinched the NL East, but their mission isn’t over. Not when Cristopher Sánchez and teammates have their eyes set on the club’s first World Series in nearly 20 years.

Sánchez had shown flashes in the past, even earning All-Star honors last year, but he’s taken another step this season. The 28-year-old is one of several starting pitchers for playoff-bound teams — or, at least, teams holding a playoff spot as of Sept. 16 — whose breakout comes just as the postseason begins.

To qualify for this list, we focused on pitchers whose 2025 season represented a clear evolution. Players like New York Yankees lefty Carlos Rodón, who struggled in 2023 and had a mixed 2024, didn’t qualify; his 4.3 bWAR and 3.11 ERA over nearly 200 innings are in line with expectations for a $162 million contract.

As for our list proper, let’s start with the newest face of the Phillies’ rotation.

Cristopher Sánchez, Philadelphia Phillies

Expectations were likely high for Sánchez following his impressive 2024, but we’re skeptical that few saw this coming. Sánchez entered Tuesday having posted 7.0 bWAR, trailing only Paul Skenes (7.4) among pitchers leaguewide. In fact, only Aaron Judge (8.3) and Skenes have a higher bWAR than Sánchez, who is quickly outperforming the four-year, $22.5 million extension he inked in June 2024.

“I’ve been around a long time, as we know,” Phillies manager Rob Thomson said earlier this month, “and I’m not sure I’ve ever seen the evolution of a pitcher like I have with Sánchez.”

Sánchez has maintained a 5.8% walk rate for the second straight season, but his strikeout rate has climbed from 20.3% to 26.0%. With Zack Wheeler (blood clot) out for the season, expect Sánchez to take the mound in the Phillies’ first playoff game, whether that comes in the NL Wild Card Round or the Division Series.

Bryan Woo, Seattle Mariners

All eyes in Seattle are on All-Star catcher Cal Raleigh, but Bryan Woo has quietly anchored the Mariners’ rotation. The 25-year-old owns a 3.02 ERA and a 191-35 K-BB ratio in 181⅔ innings, and he’s expected to start Seattle’s postseason opener.

His walk rate has risen to 4.9% from 2.8% last season, and he’s allowed 26 home runs over 29 starts. Still, Woo has increased his strikeout rate to 26.8%.

“As a staff, we know how good we can be,” Woo said following a 13-strikeout performance against the Angels on Sept. 13. “We’ve been saying it all along: As long as guys stay healthy and we can get that momentum going at the right time of the year, we’re as good as anybody.”

Clay Holmes, New York Mets

We debated including Mets ace David Peterson, whose 2.3 bWAR outpaces Holmes’ 1.5, but context matters. The Mets moved Holmes — an All-Star closer with the Yankees — into the rotation this offseason, and he’s delivered a solid first season as a starter.

Holmes has posted a 3.75 ERA with a 122-62 K-BB ratio in 151 innings while allowing just 12 home runs. He isn’t an ace, but he’s a reliable middle-of-the-rotation arm who should log at least 160 innings barring injury or late-season struggles. His postseason track record with the Yankees — three runs allowed in 20 innings — offers some optimism for October, too.

Jason Alexander, Houston Astros

Save your “Seinfeld” jokes, at least for the time being. The 32-year-old Alexander has greatly boosted the Astros, posting a 2.76 ERA and 1.8 bWAR in 12 games (11 starts) since Houston claimed him off waivers in mid-May. Although we’re concerned with Alexander’s 7.0% walk percentage in 65 1/3 innings, we do like how he feels about himself.

“I just have the confidence right now,” Alexander said after pitching seven scoreless innings against the Toronto Blue Jays on Sept. 11. “I’m confident in what I feel like I need to do out there, and all that really matters is execution.”

Confidence is key, especially in the postseason, and the Astros should be ecstatic to hear that a career minor-leaguer believes in himself right now. Even if Alexander winds up pitching out of the bullpen in the playoffs, it’s clear that he’s earned Astros manager Joe Espada’s trust at the right time.

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