Why I’m still hopeful about DJ LeMahieu

Heading into the season, the Yankees had a starting rotation full of question marks and a motley bullpen mix of aging veterans and high-upside yet inconsistent young arms. That was all in the plan however, as it was expected that a slugging-heavy lineup from top to bottom would more than make up for deficits at other parts of the roster. Instead, the rotation exceeded anyone’s expectations while the bullpen was rebuilt on the fly into one of the most dominant relief units in baseball. The pair carried a woefully underperforming offense to a Wild Card berth, with DJ LeMahieu’s regression a major factor in the offense’s demise.

Last week, I wrote about the troubling case of LeMahieu, and questioned whether it was wise for the Yankees to sign him to a six-year deal following the 2020 season. The Yankees locked him up long-term based on his impressive performance over the previous two seasons, and I worried that the player they thought they were keeping in pinstripes no longer existed. Today, I’d like to look at LeMahieu through a more optimistic lens and explain why I think there is still hope that New York can recover at least some of the 2019-20 version.

Yesterday, it was revealed that LeMahieu had successfully undergone core surgery to repair a sports hernia. The injury landed him on the IL in the final week of the season and prevented him from being added to the Wild Card Game roster (not to mention that he also had to deal with a triceps injury for much of the second half). The million dollar question: How long was LeMahieu trying to play through the hernia, and if it was an extended period of time, was that the root cause for his regression at the plate in 2021?

I noted last week how LeMahieu struggled to impact the ball with the same authority that made him so potent in the prior two seasons. Baseballs exited his bat a mile per hour slower while his hard-hit and barrel rates declined 4.2 and 2.6 percentage points respectively. If the hernia was a yearlong issue, it’s easy to see how that would rob him of power and interfere with his hitting mechanics.

LeMahieu is at his best when he is driving outside pitches to the opposite field with authority and staying inside middle-in pitches with an up-the-middle approach.

A perfect example is from the 2020 ALDS. LeMahieu is able to keep his hands inside a 97 mph Blake Snell fastball and laser it back through the box. He stays behind the ball the whole way and bangs it with the barrel of the bat. It’s evident that it is a pure strike from the lack of top or cut spin on the ball as it whizzes past Snell.

Contrast that with this swing on a similar pitch this season. He can’t hold the separation on the swing and has to pull off it. The result: a foul popup on a pitch that was right in his wheelhouse in 2019 and 2020.

Playing injured — and particularly with a core injury — robs one of mobility. Perhaps this is why LeMahieu was unable to get as deep a turn, making it that much more difficult to drive balls to the opposite field.

Again we see a prototypical LeMahieu base hit from 2020. You can see how quickly he’s able to swivel to create room to pull his hands in on a pitch that should have jammed him, as well as the flexibility to maintain a stable power base to drive the ball.

This year, that flexibility was notably lacking. He’s slow to clear his front side and as a result, the chain of movement gets jammed up. All he can do is weakly roll over this inside pitch for a harmless groundball.

LeMahieu isn’t the first Yankees to suffer from a sports hernia in the last few years. Luke Voit missed a month of time in the second-half of 2019 with a sports hernia of his own — an injury which required surgery that offseason (as it happens, LeMahieu’s surgeon was the same one who treated Voit’s hernia). There are a lot of parallels between LeMahieu’s 2021 dip in form and Voit’s struggles at the plate trying to play through the hernia in 2019. Voit posted a 136 wRC+ pre-injury and 80 wRC+ afterward, displaying much of the same difficulty driving the ball as LeMahieu.

Here’s a clip of Voit pre-injury:

And post:

Compared to his swing pre-injury, Voit looks stiff and immobile as he clearly was not firing on all cylinders.

With all this being said, there is no explicit confirmation that LeMahieu was playing through injury all season, and we cannot definitively say that his regression was solely injury-caused. Do not despair. There are some injury-independent trends from 2021 that give me hope for a 2022 LeMahieu rebound.

Just as I pointed out how LeMahieu was the luckiest hitter in baseball in 2020, one could make the case that he was one of the unluckiest in 2021. Among all qualified hitters, LeMahieu performed the worst of anybody against pitches in the “heart” zone as defined by Statcast. I fully expect a bounce-back in this category — like I said last week regarding LeMahieu having the largest delta between wOBA and xwOBA, it’s much less likely that a player can continue to live at the extremes than regress to the mean.

In addition, LeMahieu’s batted-ball types very closely resemble those from his 2019 campaign. In particular, his ground-ball rate, fly-ball rate, up-the-middle rate, and opposite-field rate are right in line with his 2019 numbers. In other words, he was employing the same approach in 2021 as the one that garnered him a top-five MVP finish in 2019. The solid foundation still exists, now it’s all about rebuilding on top of it.

I’ll qualify all this by saying that I think the days of DJ LeMahieu as a 140-150 wRC+ hitter are long gone. He was probably punching above his weight to produce those results in 2019 and 2020, no doubt aided by the juiced ball.

However, I think it is perfectly reasonable to remain optimistic about a resurgence to an above-average hitter who plays sure defense at multiple positions. We’ll probably never learn the extent to which the sports hernia contributed to his 2021 struggles, but it’s reassuring to know that Voit only went and became the MLB home run champion the season immediately following core surgery to fix his sports hernia. One can dream anyway.