Sean Manaea Might Be Salvageable, If Mets Can Live With Being Boring

The 2024 New York Mets feel like a distant memory. While it hasn’t even been 24 months since Grimace’s first pitch turned the Mets into a juggernaut, it might as well have been the pivotal moment in the Revolutionary War. A late-season collapse in 2025, followed by the fast-moving ecological disaster to start 2026, has all but erased what felt like, for a fleeting moment, the beginning of something special. And no player has embodied the rollercoaster quite like Sean Manaea. 

Manaea was a revelation for the 2024 Mets. He made 32 starts, totaling 181.2 innings, and posted a 3.47 ERA. A season after being moved to the bullpen in San Francisco, Manaea earned the right to start four playoff games for the Mets, and it was in large part thanks to him lowering his arm slot. 

The truth about hitting is that it is fundamentally subconscious. There just isn’t enough time to see, think, and react to a pitch moving 90-plus MPH. What this means for pitchers is that being generic is the worst thing possible. The more generic a pitch is, the more times a hitter has seen it, and the easier it is for them to square it up or spit on it. 

Manaea always had a weird profile. His sinker and four-seam fastball might be the same pitch. The former has more horizontal movement and vertical drop than average, but is usually thrown at the top of the strike zone. The general rule is that sinking fastballs play best at the bottom of the zone, while high-spin ones dominate at the top. 

Despite all this, Manaea limited fly balls, threw enough strikes, and got hitters to chase his sweeper or changeup on his way to being a mostly league-average pitcher. It was an effective plan, but it was mostly generic, until all of a sudden, he wasn’t. 

With the Mets in 2024, Manaea made the bold decision to lower his arm angle and completely transformed his fastball into an unstoppable weapon. While pitch characteristics are important, they aren’t the only factor in determining how a pitch will play. A lower arm angle provides pitches with a flatter approach angle, which generally makes them play better at the top of the zone. The combination of a sinking-tailing fastball from a shallow approach angle at the top of the zone made Manaea’s fastball far more unique, and helped him and the Mets to a second-half surge. 

So, what has gone so wrong for Manaea since 2024 and, in particular, 2026? Well, it’s complicated. First, his 2025 wasn’t nearly as bad as it looked. His xERA was 4.00, his FIP was 4.39, and his xFIP was 3.30. In fact, he posted the best K% (28.5%) and K%-BB% (24%) of his career, but was undone by a career-worst home-run-to-fly-ball ratio of 19.4%, which is how he posted a 5.64 ERA, despite some solid indicators. Unfortunately, the same cannot be said of his 2026. 

There is no way around it: Manaea has legitimately been awful to start the season. His xERA is 5.52, his FIP is 4.48, and his xFIP is 4.58, despite throwing exclusively out of the bullpen. So, while he has been unlucky to have a 6.85 ERA, it’s not like he’s making a case to re-enter the Mets' rotation.

The biggest concern facing Manaea has been his fastball. Usually, pitchers experience some form of velocity bump when throwing out of the bullpen, but Manaea’s average fastball velocity has dropped to 90.2 MPH, down from 91.7 in 2025 and 92.2 in 2024. No matter the secondary characteristics or the location, at a certain speed, any fastball is vulnerable. And to make matters worse, he’s locating it far worse. 

Manaea’s fastball has played relatively well at the top of the zone, and has characteristics where it could play near the bottom, but what you cannot do is throw a 90 MPH fastball down the middle, and that’s exactly what he has been doing this season. 

Sean Manaea 2026 Four Seam Heat Map

Unsurprisingly, the pitch has surrendered an xSLG of .537 and has seen its whiff rate drop from 23.2% to 18.2%. 

The reality is that Manaea’s fastball velocity might never return. He’s 34, and his velocity has been trending down over the past few seasons, despite throwing more innings out of the bullpen. However, that doesn’t mean his fastball can’t play far better if he can manage to locate it more consistently at the top of the zone and out of the heart of the plate, and despite the awful results, there are still a few things under the hood that the southpaw is doing well. 

His infield fly ball percentage of 17.2%, which, when paired with a 41.4% fly-ball rate, means that 7% of all the batted balls he has allowed are infield fly balls. Infield fly balls are historically converted as outs at nearly the same rate as strikeouts. When added to his current 22% K%, he's still getting nearly automatic outs in 27.08% of plate appearances. That's not elite, but it's something to build upon.

Manaea's first pitch strike percentage is also down to a career-low 59.3%, but in his excellent 2024, it was 59.8%. In all likelihood, his first pitch strike percentage should regress towards his career average of 63.1%, which will help cut into his career-high 9.3% BB%, and probably lead to slightly better strikeout figures and batted ball metrics.

With the loss of velocity, Manaea’s days as anything but a spot starter might be over, but there’s a road map for him to be a viable member of a bullpen. All he needs to do is locate his fastball a bit better, and he should start to look like the league-average pitcher he has been for most of his career. That's not particularly exciting, but the Mets, and Manaea for that matter, need boring competence more than anything.