MLB Slump Watch for These Struggling Hitters and Pitchers

If a hitter or pitcher must go into a slump during any given MLB season, earlier is better than later.

This is another way of saying we're not about to apply the Panic Meter to 10 hitters and pitchers who are struggling early in the 2025 season. They have lots of time to figure things out, and it's not like any of them can get worse.

Nonetheless, these guys' slumps deserve to be put under the microscope. And while we won't be busting out the Panic Meter, we will dust off the Concern Meter and narrow its settings to Low, Medium and High.

In making selections for this list, our barometer was changed in weighted on-base average from 2024 to 2025. It's not a well-known stat, but it's an effective catch-all that more or less mimics OPS.

Without further delay, let's start with five slumping hitters and end with five slumping pitchers.

Note: All advanced stats are current through play on Sunday, April 13.

wOBA Change from 2024 to 2025: Minus-.133

One of the remarkable things about Mark Vientos' 2024 breakout is just how consistent he was. His OPS never got lower than .837, if you can believe it.

This is why it feels so weird that he's this cold out of the gate in 2025, with eight hits and no home runs to show for 58 at-bats. The entire Mets' offense has been slow to wake up, sure, but this is something else.

Yet this is also a case where there's an apparent method beneath the madness.

Vientos is bordering on being too passive on in-zone pitches, but he's lopped a big chunk off his 2024 chase rate and has benefited accordingly. He only has four more strikeouts (13) than he does walks (nine) after whiffing 102 more times than he walked in 2024.

Only 33.3 percent of Vientos' batted balls have been 95 mph or above, but his average exit velocity is a sturdy 90.0 mph and he's getting the ball in the air more often than not. It'll do for a sign that he hasn't sacrificed power after hitting 27 homers last year.

Concern Meter: Low

wOBA Change from 2024 to 2025: Minus-.152

Willson Contreras showed signs of life over the weekend, collecting two hits on Saturday and Sunday and his first homer of the season during the latter.

Even still, he's just 10-for-61 on the season. And this is his first campaign as a full-time first baseman, where the pressure to produce at the plate is much higher than it is for his old haunt at catcher.

At 76.1 mph, Contreras' average bat speed remains elite. And as such, it's likely just a matter of time before he reverses the 4.8 mph drop in his average exit velocity.

The bigger concern is a strikeout rate that has skyrocketed from an already high 26.8 percent in 2024 to an even higher 33.3 percent in 2025. This is partially self-inflicted by way of a huge increase in his chase rate.

This is potentially correctable so long as Contreras or the Cardinals get wise to the new scouting report on him. He's simply not getting fastballs to hit, so he needs to tighten things up with his approach.

Concern Meter: Medium

wOBA Change from 2024 to 2025: Minus-.175

Carlos Correa has had occasional down years throughout his career, but what we're talking about here is proper iciness. He's just 9-for-59 with nary a long ball.

The best defense of Correa right now is that April usually is a chilly month for him. He has a .764 OPS in the month for his career, compared to .822 overall. When the weather warms up, so does he.

What is unusual, though, is for there to be wild swings in his average exit velocity depending on the month. He's way down in that department right now, averaging 86.9 mph next to a career norm of 89.9.

This doesn't track with his bat speed being just fine at 74.0 mph. And while he doesn't have much to show for it yet, his whiff rate against fastballs is down.

Correa's ability to square the ball up is also still there, and there's nothing to suggest he's gotten out of what's always been a strong approach. He should only need time to get right.

Concern Meter: Low

wOBA Change from 2024 to 2025: Minus-.175

Alec Bohm came into this year needing to turn over a new leaf after things went bad for him in 2024, so it was a good sign when he raked in spring training.

Now he's ice-cold with just 10 hits (including just two extra-base knocks) in 64 at-bats. And to hear it from him, he'd rather not have everyone obsessing over how he's hitting right now.

"I feel like everything is very, very overanalyzed that I do on the baseball field," Bohm said Saturday, per Todd Zolecki of MLB.com. "From the moment I step on it to the moment I step off it. But again, that's out of my control."

He might be trying a little too hard to bust his slump, as he's added quite a few points to his chase rate and walked only once in 65 plate appearances. Given his own propensity for dwelling on his failures, one does worry about a potential spiral.

The good news? Bohm's contact quality is actually excellent, as seen in his 92.2 mph exit velocity and 51.1 hard-hit percentage. Both are up from 2024, when he was a first-time All-Star before things unraveled.

Concern Meter: Low

wOBA Change from 2024 to 2025: Minus-.242

The entire Rangers offense has struggled out of the gate, but nobody more so than Joc Pederson. He has three hits and zero homers in 43 at-bats.

It's a stunning about-face after the 32-year-old posted a .908 OPS as a lefty platoon hitter in 2024, throughout which his metrics painted a generally rosy picture. His expected wOBA was on par with Francisco Lindor and Gunnar Henderson.

This is not the case so far in 2025, and there are legitimate contact quality concerns at play.

Pederson's hard-hit rate is way down from last season, while his ground-ball percentage has skyrocketed to 58.1. That is never ideal, but least of all when the player in question is not a burner.

At 73.6 mph, Pederson's bat speed is more than fine. Yet pitchers seem convinced they can beat him up and in with fastballs, and they'll be right as long as he continues to jam himself on those.

Concern Meter: High

wOBA Change from 2024 to 2025: Plus-.114

Corbin Burnes does tend to be a slow starter, posting a 3.73 ERA in April compared to a 3.22 ERA overall.

This doesn't excuse an ERA as high as 5.28, though, and it's odd to see the 2021 NL Cy Young Award winner struggling so much with his control. He's walked nine batters in 15.1 innings, but his rate of pitches in the zone has not plummeted.

As such, more alarming is how hard batters are hitting Burnes. His hard-hit rate is up 22.9 percentage points from 2024, putting him among the worst of the worst of the movers in that department.

It wouldn't seem to be helping matters that his cutter and sinker are both roughly 1 mph below his career averages. The former is his signature pitch, and batters have gone from slugging .362 against it in 2024 to .571 so far in 2025.

Burnes isn't going to be down this far for the whole season, but his early hittability is an unwelcome variation on a theme. This was also an undercurrent of his 2024 season, in which his strikeout rate was decidedly mid in the 51st percentile.

Concern Meter: Medium

wOBA Change from 2024 to 2025: Plus-.118

April does tend to be Chris Sale's worst month, and it bears noting that he had a shaky start to 2024 before going on to win the NL Cy Young Award.

This isn't to say there aren't real warning signs at work. His average fastball is down 0.7 mph from last season and getting demolished to the tune of a .524 average and .762 slugging percentage.

This sounds bad, and indeed feels ominous on account of Sale's age and history. He's 36 years old and his brilliant 2024 season is a major outlier for his career dating back to 2019.

On the plus side, he got up to 96.2 mph with his average fastball on Sunday and missing bats hasn't been an issue in any of his four starts. In all, his 30.3 whiff rate is in the 75th percentile.

Further, Sale's hard-hit rate is barely up relative to 2024 and he's shown his usual strong control in only walking four batters in 19.0 innings. His 6.63 ERA should be coming down soon.

Concern Meter: Medium

wOBA Change from 2024 to 2025: Plus-.131

Edwin Díaz has a 7.94 ERA through six appearances, in which he's given up six hits and four walks, plus two hit-by-pitches and four wild pitches.

Yet the Mets like what they see, with pitching coach Jeremy Hefner saying (via Mike Puma of the New York Post) on Saturday: "Overall, the stuff and the spin rates and all those things are pretty normal."

However, it's hard to determine what Hefner is looking at. Both the average velocity and average spin rate on Díaz's fastball are down from 2024, as is his overall whiff rate from 38.8 percent to 33.3 percent.

It would also be understating it to say the righty is struggling to find the strike zone. Only 42.9 percent of his pitches have hit it, which is low even for a reliever.

It's still worth having faith in Díaz because of his track record, not to mention how well he recovered after struggling badly enough to lose his job early in 2024. But for now, it suffices to say this year's struggle is not a mirage.

Concern Meter: High

wOBA Change from 2024 to 2025: Plus-.174

The problem isn't so much that Raisel Iglesias has a 4.50 ERA. That's not great, but it's not terrible either.

Rather, the issue is that he's given up three home runs in 6.0 innings. He's already one homer away from matching his total from 2024, when he pitched 69.1 innings.

There's a usual suspect fouling things up here, in that Iglesias' average fastball is down 1.3 mph from last season. Given that he's 35 years old, how much velo he'll be able to add as the year goes on is a fair question.

And yet, it's not the fastball that has gotten him in trouble. Batters are actually 0-for-6 against it, compared to 4-for-15 with all three of those homers against his slider and changeup.

Does he need to be careful about hanging sliders? Obviously, yes. But the homer he gave up to Shohei Ohtani on a changeup wasn't so much a bad pitch as Shohei Ohtani doing a Shohei Ohtani thing.

Concern Meter: Medium

wOBA Change from 2024 to 2025: Plus-.256

Emmanual Clase gave up five earned runs throughout the entire 2024 regular season. He's already given up six in 2025, along with 14 hits in seven innings.

This is why people have trust issues with relief aces, and Clase has notably lost 0.6 mph off his cutter from last season. It's still a 98.9 mph cutter we're talking about, but its margin for error counts given how often he throws it.

Yet it isn't out of the ordinary for the 27-year-old to start off relatively slow with his cutter in April. And the pitch even has some solid peripherals right now, including an elevated whiff rate of 33.9 percent, up from 24.5 percent in 2024.

Clase's hard-hit rate is up from last season, but modestly so in the scheme of things. And of the 14 knocks he's given up, eight fall under the hard-hit threshold of 95 mph. There's been some bad luck at play on those.

As such, the Guardians don't have a doomed closer on the hands. What they have is more like one who was destined to regress eventually.

Concern Meter: Low

Stats courtesy of Baseball Reference, FanGraphs and Baseball Savant.