The San Diego Padres Need Jackson Merrill To Recover His Power Stroke

[Randy Holt]

It's difficult to criticize the season Jackson Merrill is turning in thus far in 2025. It might even be unnecessary. The San Diego Padres' star centerfielder has worked through a hamstring injury and a week-long stay on the concussion IL to turn in a .303/.347/.474 line, a bump in the walk rate, and, ultimately, a 130 wRC+. When healthy, he's been very, very good. 

However, a Padres squad that has struggled to produce runs consistently over the past month needs him to be even better, specifically in terms of his power production. 

It's a tough ask for a player who has dealt with a non-contact injury and a concussion to date. But it was a bar Merrill set last year when he turned in a .208 isolated power figure and hit 24 home runs. This year, the former sits at .171 and the latter at just five. With the Padres sitting 27th in the league in that regard (.130 ISO team-wide), a bump in the power game from Merrill seems like an obvious route toward collective offensive improvement. 

Not that it's solely on Merrill to sort out the power side. That we know it's there, given the upside and the output from 2024. Where has it gone, exactly? A 37 percent drop in ISO isn't insignificant, and Merrill has seen a notable decline in Hard-Hit% between 2024 (43.9) and 2025 (38.2), whether there's a clear explanation — and, as such, an apparent fix — remains to be seen. 

The approach, in a broad sense, has regressed a bit: 

He's been a bit more aggressive, both inside and outside the zone. In doing so, he's subjected himself to more whiffs and less overall contact. While it's not anything drastic in terms of his 2024 trends, reigning in the discipline a bit could help him to realize some of that power upside more frequently. However, we can also refine this approach a little further.

One possible explanation for the power decline is in the types of pitches at which Merrill is swinging. Off-speed pitches, in particular, represent a source of woe for Merrill in the small sample that has been his career. Merrill has been able to muster a slug against off-speed pitches just 25.9 percent of the time this year, compared to 47.7 vs. fastballs and 56.7 against breaking pitches. It's not an aberration either, as his expected slug against the pitch type is just 35.1 percent, nearly 20 points lower than his expected slug against either of the two other pitch types. 

Yet, Merrill is hacking at off-speed pitches more than any other pitch type: 

That's a Swing% of 65.6 against that pitch type, not only a drastic increase from 2024 (54.7), but also his highest rate against any of the three types by a significant margin. He's chasing (44.6 percent) and whiffing (28.8 percent) at that pitch pretty severely in comparison to the other two types. To say nothing of a 63.6 percent groundball rate when he does make contact. He's in the low 40s in GB% when the other two types of pitches are put into play. 

So, it's not only that he's having a tough time making contact to begin with, but it's also something that we can point to in pinning down his overall power output. If it were a situation where those numbers existed but he was minimizing the actual swings, then we probably wouldn't be wondering where the power went. But because such a high volume of swings against off-speed exists, it looks like an easy explanation. 

The good news is that it's not as if pitchers are suddenly throwing a bunch of off-speed at Jackson Merrill in comparison to last year. He's seeing less of it this year, at just 14.2 percent. It's the lowest frequency of any of the pitch types. Merrill's just subjecting himself to it at a higher rate. 

Which, despite the outcomes, does read as a positive. There is nothing in the mechanics to suggest that a path or attack angle has changed, and the only noticeable change in the zone is a slight drop in his swing frequency. However, because Merrill is able to derive much of his power from that area anyway, there is no conversation worth having about the zone itself. 

For Jackson Merrill, it very much does seem to be rooted in the approach. While it isn't hurting his overall game, it is sapping him of some of his power potential. It's important to consider that the two separate injuries could have stalled his progression in matters of the approach. Now clear of the second one, perhaps he now has the runway to settle in, at which point, the Padres would get the power boost they so sorely need.

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