What must Mark Teixeira do to turn his season around?

This weekend, Mark Teixeira made his return from the disabled list after a three week absence. It was a welcome sight to see him launch a solo home run on Sunday against the Twins, as the majority of Teixeira’s at-bats this year have been tough to watch. After a resurgent 2015, Teixeira spent the first two months of 2016 producing outs at an alarming rate, and generally looking like a shell of himself.

This is an issue, as Teixeira’s surprising performance was a crucial part of the Yankees’ success last season. In 2015, Teixeira produced an excellent .255/.357/.548 triple slash line. His 143 wRC+ was his best since 2009, and was the highest such mark on the team. In 2016, his line nearly resembles that of a pitcher’s, at .179/.272/.277. By both Baseball-Reference and Fangraphs’ value metrics, Teixeira has been well below replacement level this year.

Both Teixieira and the Yankees’ offense had a revival in 2015, and they’ve both struggled in 2016. It might be a long-shot, given his tremendously poor start to the season, and his anything but clean bill of health, but something resembling a return to form for Teixiera would be a needed boost to the Yankee lineup. He has struggled in nearly every facet of the game, but here are a few key changes that need to occur for Teixeira’s return to be successful.

Hit the ball in the air again

Teixeira’s success as a hitter in the past has in no small part been borne out by his power stroke. He hits the ball in the air, and he hits it far. For his career, Teixeira owns a fly ball rate of 40.5%, and a HR/FB rate of 18.2%, both well above league average.

That has been far from the case this year. His groundball rate has skyrocketed all the way to 48.3%. Never in his career has Teixeira posted a groundball rate greater than 42.8%. His fly ball rate has plummeted beneath 30%, and merely 9% of his fly balls have gone for home runs.

With Teixeira rarely putting the ball in the air, it is no wonder his power numbers have disappeared. His home run on Sunday was just his fourth of the season, and his Isolated Slugging figure of .098 is by far a career low (his career low ISO for a full season is .182). As the owner a career OPS of .436 on groundballs and 1.118 on fly balls, Teixeira needs to stop putting the ball on the ground in order to turn things around.

Regain his lefty stroke

Teixeira has long had a reputation as one of the game’s finest switch-hitters. It is a well-deserved notion, as Teixeira for his career has been great from both sides of the plate. However, his left-handed stroke his deserted him in 2016.

For his career, Teixeira has hit right-handers at a .261/.352/.510 clip, while his line against left-handers is a slightly stronger .290/.384/.516. This year, there has been a wide disparity in Teixeira’s performance on either side of the plate. Against righties this year, Teixeira has put up a dismal .138/.230/.229 line.

It appears right-handed pitchers have taken extra advantage of Texieira’s weakness on breaking balls low and in. Here’s his zone profile against right-handers this year, courtesy of Brooks Baseball:

It makes sense that Teixeira has seen a ton of pitches down and in, as he has whiffed on an ugly 69.7% of swings at pitches in that area for his career. If Teixeira can’t cover that hole in his swing, and regain his form from the left side of the plate, his value as a hitter will be severely limited.

Manage his struggles against slow pitches

Teixeira, like many power hitters, has made his name crushing fastballs. Entering this year, he had slugged .525 against four-seam fastballs, and .602 against two-seamers. His strength against hard stuff was his calling card, but he also was completely serviceable against off-speed and breaking pitches.

Not so this year. In 2016, Teixeira has looked utterly incompetent when faced with pitches like sliders, curveballs, and changeups. In at-bats ending with such pitches, Teixeira has hit .174, with merely one extra base hit.

During his 2015 campaign, Teixeira managed a line drive or fly ball on over 50% of balls in play against changeups, sliders, and curves. That rate has fallen to 37% against changeups, 44% against curves, and an even 0% against sliders. The samples are small, but the results are too extreme to completely ignore; if Teixeira continues to hit like this against off-speed and breaking offerings, his struggles will linger all season.

In truth, Teixeira’s opening months were a nightmare where nearly everything went wrong. I’ve highlighted some of Teixeira’s biggest troubles thus far, but his difficulties have extended even beyond them. Still, if these glaring issues aren’t fixed going forward, Teixeira’s season may simply be doomed. The Yankees must hope Teixeira can solve these problems and contribute, or else they’ll be forced to turn to the likes of converted second basemen and waiver wire retreads to fill their hole at first base.