Jackson Merrill Is (Finally) Letting His Barrel Do the Talking

When the 2025 season got underway, it looked like San Diego Padres centerfielder Jackson Merrill was on his way to building on a strong rookie campaign. At least through the first 10 games of the season.

Through that initial stretch, Merrill hit .378, reached base at a .415 clip, and posted an obscene 201 wRC+. The approach seemed to show some early refinement, with a walk rate a touch over seven percent. The most exciting component, however, was on the power side. Merrill's first 10 games featured a pair of doubles and three home runs on his way to a .297 ISO. 

None of this was sustainable, of course. It was largely the byproduct of a small sample. The results remained encouraging until a hamstring injury in early April. Then, there was the concussion in June, followed by an ankle injury after rolling it out of the box against the Los Angeles Dodgers last month. In short, the opportunities for Merrill to find a groove amid multiple injury issues have been scarce. It led to some fairly underwhelming numbers for the 2024 Rookie of the Year runner-up through the end of August. 

On August 31, Merrill carried a .261/.317/.413 line with a 105 wRC+. His strikeout rate (21.2 percent) exceeded last year's rookie mark (17.0). Most concerning was the absence of power, as Merrill's .152 ISO to that point represented a more than 50-point drop from last year's output (.208). That mark, as it stood, was also somewhat carried by his strong start given that he had individual months of .143, .100, and .109 in the ISO game, successively from May to July.

There were signs last month that Merrill was due for a bit of a breakout in that respect, as he'd posted a .214 ISO prior to his third trip to the Injured List in '25. September, though, has seen an even better rebound than anticipated.

Merrill's overall numbers this month (through nearly three weeks of play) are quite good. His .278 average is his best since May and his .316 OBP, while modest, is his top on-base rate since June. There are some notable trends on the strikeout & walk side, but the most notable element for our purposes lies in the power. Merrill is carrying a .407 ISO as of this writing, courtesy of three doubles, two triples, and five homers. It's not a complicated trend to explain either: 

Merrill's barrel rate has skyrocketed, with a 23.7 percent barrel rate on batted ball events thus far in September. That's an even 17-point jump from the rate he'd posted in August. It's a trend that comes largely courtesy of his work against fastballs. Merrill is swinging at fastballs more than any other pitch type this month (59.7 percent) with the hard stuff accounting for a 29.7 percent barrel rate. That's 13 percent higher than the next closest pitch type (off-speed). 

That Merrill is doing such impressive work against fastballs is a development of the utmost importance given where some of his trends against the other pitch types sits at present. He's whiffing at over 60 percent of off-speed pitches overall and nearly 37 percent of breaking pitches. Each one stands in heavy contrast to fastballs, where he's whiffing just 20.8 of the time. It's the pitch he's swinging at the most overall and chasing the least. On that side of his approach, at least, Merrill is demonstrating a sense of command on the hard stuff. 

That doesn't mean that there aren't adjustments that could help him to sustain some of this production, especially in terms of pitch recognition. Merrill doesn't have an abnormal swing rate overall, but he's striking out more than 28 percent of the time thus far in September. Such volume has come due to a 41.7 percent strikeout rate on off-speed pitches and a 38.5 K% on breaking pitches. Recognition seems key, as pitchers this month are throwing Merrill fastballs at a rate over 58 percent. That's sure to come down as they adjust. The good news is that we know Merrill to be plenty capable of doing this type of work beyond the fastball, as he had two months in 2024 where his barrel rate against off-speed pitches was the driver of his production.

Remaining adjustments notwithstanding, this still sits as a crucial development for the Padres' center fielder. The 2025 campaign has predominantly been a year of woe for Jackson Merrill. The footing on the power side simply has not been there outside of that 10-game sample to start the year. That he's dialing in his approach to be aggressive on fastballs—and finding the desired outcomes as a result—could not be a more welcome development for a team in need of offense up and down the roster as October looms.