Is He Cooked? Buy or Sell Big MLB Players' Sharp Declines in 2025
Here at the end of MLB's 2025 regular season, things look a little different than they did back in March.
In particular, it's OK to be gobsmacked by star players who didn't put forth star-caliber performances this season. There are 10 in particular (five pitchers and five hitters) who we want to talk about, with one question in mind: Are they cooked?
This involved getting into the weeds and looking for signs of how they have really performed. Case in point, the first guy under the microscope is a pitcher whose ERA shot up by more than a run from 2024, even though he didn't really get hit harder.
Intrigued? Then you'd better read on.
Dylan Cease, San Diego Padres
1 of 10
Age: 29
2024 Stats: 33 GS, 189.1 IP, 137 H (18 HR), 224 K, 65 BB, 3.47 ERA, 118 ERA+
2025 Stats: 31 GS, 163.0 IP, 146 H (21 HR), 207 K, 69 BB, 4.64 ERA, 93 ERA+
How Bad Is It?
It's only recently that Dylan Cease has begun to settle down. After carrying a 4.82 ERA through the end of August, he has a 3.43 ERA through four starts this month.
It's too little, too late to save his season, but don't be surprised if he cashes in as a free agent this winter anyway. Because while he's doing some things worse in 2025 than he did in 2024—namely, walking guys and allowing home runs—he's actually been better at others.
His average fastball is actually up 0.2 mph relative to last season, and his whiff and strikeout rates have taken turns for the better as well. He's even punching out lefties at a 28.4 percent clip, the second-best of his career.
Otherwise, Cease's exit velocity, hard-hit rate and barrel rate are level (or better) with the figures he posted last season. It all points to an inordinate amount of bad luck, specifically encapsulated in his top-10 highest BABIP.
Cooked Verdict: Sell
Zac Gallen, Arizona Diamondbacks
2 of 10
Age: 30
2024 Stats: 28 GS, 148.0 IP, 133 H (13 HR), 156 K, 54 BB, 3.65 ERA, 116 ERA+
2025 Stats: 32 GS, 187.2 IP, 169 H (30 HR), 172 K, 63 BB, 4.70 ERA, 92 ERA+
How Bad Is It?
Whereas Dylan Cease has only recently started getting results, Zac Gallen has been much better since the All-Star break. In 12 second-half starts, he's posted a 3.59 ERA.
The causes for this are real. The righty has upped his fastball velocity as the year has progressed, and also altered his pitch mix. So far in September, he's leaned more heavily on his changeup and benefited with a .053 average against it.
That said, this is the second year in a row that Gallen has struggled with free passes. And he can't afford to be putting runners on base like that, as he's never been much of a swing-and-miss guy. He's also become a magnet for hard contact, as this is the third year in a row that he's had subpar batted ball metrics.
Gallen might maintain his momentum next year if he carries over his improved velocity, but that's a lot to ask of a guy who just turned 30. And besides, this is now two years in a row that he has looked less like an ace and more like a mid-rotation type.
Cooked Verdict: Buy
Ryan Helsley, New York Mets
3 of 10
Age: 31
2024 Stats: 65 G, 66.1 IP, 50 H (3 HR), 79 K, 23 BB, 2.04 ERA, 202 ERA+
2025 Stats: 56 G, 53.0 IP, 59 H (8 HR), 60 K, 24 BB, 4.75 ERA, 88 ERA+
How Bad Is It?
Even relative to the extremely volatile nature of relief pitching, Ryan Helsley's decline has been shocking. And it's only gotten worse since he joined the Mets, for whom he has an 8.47 ERA in 20 appearances.
At an average of 99.3 mph, Helsley's fastball still has elite velocity. But it hasn't really mattered, as opposing hitters have gotten to it for a .424 average and a .677 slugging percentage. It's in the running for the worst pitch of 2025.
As Helsley is set to be a free agent this winter, all of this is terribly timed. And no matter what happens, even his prospective suitors will know that his control probably can't be fixed. This is the second time in three years he's walked over four batters per nine innings.
His right arm is still worth believing in, however, and there may be a fix for his fastball. He's perhaps gotten too over-the-top with his arm angle, which was lower in his dominant years for St. Louis earlier in the 2020s.
Cooked Verdict: Sell
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Aaron Nola, Philadelphia Phillies
4 of 10
Age: 32
2024 Stats: 33 GS, 199.1 IP, 189 H (30 HR), 197 K, 50 BB, 3.57 ERA, 117 ERA+
2025 Stats: 16 GS, 86.1 IP, 97 H (17 HR), 88 K, 28 BB, 6.46 ERA, 69 ERA+
How Bad Is It?
True, Aaron Nola missed about three months in the middle of the season with a sprained ankle and a stress fracture in his ribs. That'll make it hard to get on a roll.
On the other hand, he already had a 6.16 ERA when he hit the IL in May, and he's only gotten worse with a 6.87 ERA since his return in August. That looks less like rust and more like, well, general badness.
Nola's walk rate being on the low side is nothing new, and it's good that he's still striking out roughly a batter per inning. Yet this is the third year in a row that home runs have been a problem, and a career-worst barrel rate of 9.7 percent doesn't absolve him of blame for that.
Also, his 91.8 mph average fastball is his lowest since 2016. He's about at that age where you have to worry about that being the new normal, which isn't ideal for a guy who had a relatively small margin for error to begin with.
Cooked Verdict: Buy
Framber Valdez, Houston Astros
5 of 10
Age: 31
2024 Stats: 28 GS, 176.1 IP, 140 H (13 HR), 169 K, 55 BB, 2.91 ERA, 138 ERA+
2025 Stats: 30 GS, 185.0 IP, 164 H (14 HR), 177 K, 66 BB, 3.75 ERA, 112 ERA+
How Bad Is It?
Did you hear the one about the pitcher who threw at his own catcher? Framber Valdez actually did that...allegedly.
That incident is but one part of a truly ugly spiral for the lefty, who has a 1-7 record and a 6.71 ERA in his last nine starts. All of this is happening on the doorstep to his free agency, which is not what you call ideal.
However, the quality of Valdez's stuff doesn't appear to be the problem. At 94.3 mph, his sinker has about the same average velocity as it did in 2024. And while his curveball's run value is way down, its whiff rate is actually up from last year.
Valdez otherwise remains one of the hardest pitchers in the league to square up, and not just in the sense that he's third among starters in ground-ball percentage. He's also in the 76th percentile for barrel rate.
Cooked Verdict: Sell
Mookie Betts, Los Angeles Dodgers
6 of 10
Age: 32
2024 Stats: 116 G, 516 PA, 19 HR, 16 SB, .289 AVG, .372 OBP, .491 SLG, 143 OPS+
2025 Stats: 145 G, 641 PA, 20 HR, 8 SB, .258 AVG, .328 OBP, .411 SLG, 106 OPS+
How Bad Is It?
It certainly was worse, as Mookie Betts was still sporting a .600-something OPS at the end of August. He has since found his stroke in September with a .997 OPS.
As for why it took him so long, to say that Betts has had a rough year off the diamond would be putting it mildly. To wit, it was probably always going to be hard to get through a 162-game season after the awful stomach illness he had in the spring.
This is not to say there are no causes for lasting concern. This is the second year in a row that Betts has had an average exit velocity in the 80s and a hard-hit rate in the 30s, both of which are in below-average territory.
Still, you can get away with that when you put on good at-bats and thrive on pull power. Betts has continued to do both in 2025, with 60 walks against 65 strikeouts and a top-tier rate of pulled air balls.
Cooked Verdict: Sell
Nick Castellanos, Philadelphia Phillies
7 of 10
Age: 33
2024 Stats: 162 G, 659 PA, 23 HR, 6 SB, .254 AVG, .311 OBP, .431 SLG, 104 OPS+
2025 Stats: 141 G, 571 PA, 17 HR, 4 SB, .254 AVG, .298 OBP, .409 SLG, 91 OPS+
How Bad Is It?
Nick Castellanos' star power has been hanging on by a thread for a couple of years now, and it's clear that the Phillies have had enough. He's a platoon hitter, much to his chagrin.
The weird part is that Castellanos isn't having a down year because righties are overwhelming him. His .715 OPS against them is up from last year, in which he had a solid .742 OPS overall.
And yet, the percentiles on Castellanos' bat speed tell an alarming tale:
- 2023: 59th
- 2024: 52nd
- 2025: 22nd
That's an age red flag if there ever was one, and it's cutting into Castellanos' ability to handle the fastball. And that is a pitch he frankly needs to handle, as he otherwise can't help himself from chasing after breaking and offspeed stuff outside the zone.
Cooked Verdict: Buy
Carlos Correa, Houston Astros
8 of 10
Age: 31
2024 Stats: 86 G, 367 PA, 14 HR, 0 SB, .310 AVG, .388 OBP, .517 SLG, 153 OPS+
2025 Stats: 139 G, 566 PA, 13 HR, 0 SB, .273 AVG, .327 OBP, .400 SLG, 100 OPS+
How Bad Is It?
Carlos Correa has at least been healthy this year, which is the good news. The bad news is that he has regressed more than any other hitter.
There are real warning signs at play, including a 7.2 walk percentage that is well below his career norm (10.3) and a barrel rate that has sunk to the 32nd percentile. Patience and power are often considered old-man skills, so this is concerning.
And yet, Correa has better expected results on contact than he did in 2023 and 2024. He's also had a nice uptick in production (i.e., a 112 OPS+ vs. a 94 OPS+) since moving from Minnesota back to Houston, and that's despite only having a .473 OPS at Daikin Park.
As Correa had a .847 OPS at Daikin Park before leaving as a free agent after 2021, it's a solid guess that he won't remain so cold there in the years to come.
Cooked Verdict: Sell
Teoscar Hernández, Los Angeles Dodgers
9 of 10
Age: 32
2024 Stats: 154 G, 652 PA, 33 HR, 12 SB, .272 AVG, .339 OBP, .501 SLG, 135 OPS+
2025 Stats: 129 G, 526 PA, 24 HR, 5 SB, .244 AVG, .284 OBP, .448 SLG, 102 OPS+
How Bad Is It?
Teoscar Hernández has to earn his living with his bat, so it's distressing to see him among the biggest losers in on-base percentage relative to 2024.
That largely comes down to his walk rate, which is down from 8.1 to just 4.9 percent. That's the same as Luis Arraez, and the difference with him is that his lack of power invites pitchers to throw strikes.
Which brings us to the odd part of Hernández's walks: he's not actually expanding the zone more often. His problem is one of passivity, as his swing rate is down from last season, even though his rate of in-zone pitches is a career-high 54.8 percent.
It's as if Hernández has been caught off guard by this and has yet to adjust back. But that should be fixable, and he doesn't really have any glaring red flags otherwise. If he gets more aggressive, the hits should be there.
Cooked Verdict: Sell
Christian Walker, Houston Astros
10 of 10
Age: 34
2024 Stats: 130 G, 552 PA, 26 HR, 2 SB, .251 AVG, .335 OBP, .468 SLG, 120 OPS+
2025 Stats: 149 G, 619 PA, 23 HR, 2 SB, .232 AVG, .294 OBP, .399 SLG, 90 OPS+
How Bad Is It?
Christian Walker is still playing a solid first base, so his three-year, $60 million deal hasn't been a total loss for Houston so far.
They obviously expected more offensive bang for their buck, however, and even Walker's solid batted-ball metrics (especially his 77th-percentile barrel rate) only offer so much comfort.
One major cause for alarm is his strikeout rate, which has risen to 28.1 percent from 19.2 percent just two years ago. Pitchers have been pounding him with fastballs (particularly four-seamers up and away) and it's been working. In what may be a related story, he's lost 0.9 mph off his bat speed.
Ironically, Walker's walk rate is down from 10.0 to 6.5 percent. It feels like a case of him trying to swing his way through adversity, and the results aren't going to change if he can't get his bat speed back up.
Cooked Verdict: Buy
Stats courtesy of Baseball Reference, FanGraphs and Baseball Savant.
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