Offseason Deep Dives: Sean Manaea

Offseason Deep Dives: Sean Manaea

This article is part of our Offseason Deep Dives series.

Sean Manaea made lots of big changes this season, and I'm not just talking about him cutting off all his hair.

Some of those changes occurred at the beginning of the season, others in the middle. When the dust settled, Manaea had received Cy Young votes for the first time in his nine big-league seasons. He tied a new career high with 12 wins, set a new career high with a 3.47 ERA and put up the second-best WHIP (1.08) and strikeout total (184) of his career.

Manaea went undrafted in many mixed leagues last spring and was a late-round dart throw in others. He finished the year as a top-20 fantasy starter and top-75 overall player in what was his age-32 season. It's a heck of a return on investment, but with his draft price on the rise, can the southpaw keep things rolling in 2025?

In 2022 with the Padres and in 2023 with the Giants, Manaea went with a four-seamer as his primary fastball for the first time since his rookie season. He still threw his sinker nearly 10 percent of the time in 2022 but scrapped it almost entirely in 2023. Manaea had gone to Driveline in the winter prior to the 2023 campaign in hopes of unlocking more velocity and he did just that, averaging a career-high 93.6 mph with his heater. His 25.7 percent strikeout rate was the second-best mark of his career. He then landed a two-year, $28 million contract with the Mets,

Sean Manaea made lots of big changes this season, and I'm not just talking about him cutting off all his hair.

Some of those changes occurred at the beginning of the season, others in the middle. When the dust settled, Manaea had received Cy Young votes for the first time in his nine big-league seasons. He tied a new career high with 12 wins, set a new career high with a 3.47 ERA and put up the second-best WHIP (1.08) and strikeout total (184) of his career.

Manaea went undrafted in many mixed leagues last spring and was a late-round dart throw in others. He finished the year as a top-20 fantasy starter and top-75 overall player in what was his age-32 season. It's a heck of a return on investment, but with his draft price on the rise, can the southpaw keep things rolling in 2025?

In 2022 with the Padres and in 2023 with the Giants, Manaea went with a four-seamer as his primary fastball for the first time since his rookie season. He still threw his sinker nearly 10 percent of the time in 2022 but scrapped it almost entirely in 2023. Manaea had gone to Driveline in the winter prior to the 2023 campaign in hopes of unlocking more velocity and he did just that, averaging a career-high 93.6 mph with his heater. His 25.7 percent strikeout rate was the second-best mark of his career. He then landed a two-year, $28 million contract with the Mets, a deal which contained an opt-out after the first year.

Despite having just seen him have success throwing a four-seamer, the Mets immediately had Manaea go back to the sinker as his primary fastball. (More two-seamers was a common theme up and down the Mets' pitching staff.) The pitch wound up earning a plus-15 Run Value on Baseball Savant, which is the highest grade Manaea has been awarded for any offering during his career. Only Zack Wheeler, Paul Skenes, Logan Webb and Jose Soriano netted a higher Run Value than Manaea when it came to two-seamers.

The Mets also had Manaea lean into the sweeper as his main secondary pitch. The sweeper had shown promise when Manaea incorporated it more and more in 2023 with the Giants out of the bullpen, but he abandoned it down the stretch when they threw him back into the rotation. The offering finished with a Run Value of minus-3 in 2024, but a 38.8 percent whiff rate and .219 xwOBA painted a more optimistic picture.

Manaea had a solid 3.74 ERA with 101 strikeouts over 106 innings across his first 20 starts of the season for the Mets. However, a 10.1 percent walk rate was not ideal and was a continuation of a rate that had been creeping up the past couple years. After a July 24 start against the Yankees during which he walked four in 4.2 innings and turned in his second straight lackluster outing, it was at that point Manaea felt a change was necessary.

Manaea was watching video of recently-announced National League Cy Young winner Chris Sale and decided he would lower his arm slot like the fellow left-hander.

The move paid immediate dividends. Manaea struck out 11 over seven shutout innings in his first start with the new arm slot and followed that up with 10 punchouts across seven scoreless frames his next time out. All told, Manaea posted a 3.09 ERA, 0.85 WHIP and 83:18 K:BB over 75.2 innings covering his final 12 regular-season starts. The walk rate went from 10.1 percent down to 6.2 percent.

Manaea leaned into his sinker even more down the stretch, with the lower arm slot allowing him to be more effective at the top of the zone, in particular.

Sinker

 Usage%xwOBAWhiff%
First 20 starts38.35018.9
Final 12 starts55.4.29323.1

Manaea also made an additional alteration during the middle of his terrific two-month run. He had been using his changeup less and less due to its ineffectiveness, but a new grip following his Aug. 10 start in Seattle allowed him to feel more comfortable with the offering, as he details in the video here. The results with the new grip speak for themselves.

Changeup

 Usage%xwOBAWhiff%
6/14-8/107.3.46318.9
Final 9 starts12.1.20725

Manaea did a pretty good job of limiting hard contact this season, which is something he's really struggled with for most of his career. From 2016-22, he never rated higher than the 29th percentile in hard-hit rate. In 2023 he came in in the 68th percentile and in 2024 he was in the 58th percentile. He also ranked in the 54th percentile in barrel rate and 56th percentile in average exit velocity in 2024, which were both career bests.

Earlier this month, Manaea declined his $13.5 million player option and then passed on the Mets' one-year, $21.05 million qualifying offer. He's betting on a sizable, multi-year contract in free agency, which shouldn't be difficult to find even as he turns 33 in February. Yusei Kikuchi is nearly eight months older and just netted a three-year, $63 million pact from the Angels. You could argue his upside is higher, but if the changes Manaea made down the stretch of this season stick, maybe not?

In early NFBC drafts, Manaea's ADP currently sits at 175.4, sandwiched between Zach Eflin and Brandon Pfaadt among starting pitchers. Of course, where he winds up signing this winter will have a say in where that number ultimately lands.

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ABOUT THE AUTHOR
Ryan Boyer
Ryan has been writing about fantasy baseball since 2005 for Fanball, Rotoworld, Baseball Prospectus and RotoWire.
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