Gary Sanchez took the league by storm last season. He swatted 20 home runs in just 53 games, compiling a mind-boggling .657 slugging percentage. It’s no stretch to say that he was among the game’s most dangerous power threats down the stretch. While no one expected him to sustain that pace over a full season, few would have predicted the pedestrian power output he’s managed thus far in 2017.

Following Monday afternoon’s game against the Orioles, Sanchez owns a .264/.356/.418 batting line. Figure in his four home runs and that works out to a respectable 116 wRC+. Yet this feels disappointing when compared to his performance in 2016. Certainly regression was expected, but Sanchez has yet to piece together a prolonged hot streak. What could explain his struggles to date? A close analysis raises more questions than answers.

When a player suffers a drop in power, it proves useful to look groundball percentage vis-a-vis hard contact rate. Typically a struggling player sees an increase in the former while a drop in the latter. For Sanchez, however, he’s experienced a dip in both categories. Here’s a chart of his batted ball types in 2017:

Now compare that to his 2016 profile.

The good news is that Sanchez isn’t showing a spike in groundball percentage. The fact that he’s cut down on the number of grounders is rather encouraging. The drop off in hard contact, however, isn’t. That speaks to his power outage, but doesn’t explain why it’s happening. For that information, one has to dig a little deeper.

While Statcast has popularized exit velocity as a way to measure hard hit balls, launch angle proves just as illuminating. Balls that leave the bat at a 25 - 30 degree angle typically result in home runs. Sanchez lived in that territory last season.

This year, however, he’s having a difficult time generating the proper launch angle.

This suggests that some part of his swing isn’t the same as last season. He’s not squaring the ball up like he did when he went on that tear. The issue could be mechanical, or it could be a physical problem. That latter suggestion rings a few bells, considering Sanchez missed approximately a month with a strained biceps. It’s possible that the Yankees catcher still hasn’t regained his power stroke. The injury has healed, but his timing could still be off.

Pinpointing an exact cause for Sanchez’s power outage proves difficult. There are a number of possibilities, but none stand out as an individual culprit. What is clear, however, is that the Yankees desperately need him to regain form. The lineup has struggled of late, averaging just 3.28 runs over the last seven games. Aaron Judge has done a tremendous job carrying the team in the power department, but it would be nice to give him some coverage.

Nobody is looking for Sanchez to repeat last season’s pace. That would be terrific, but it’s unrealistic The Yankees just need him to hit closer to his potential. The pedestrian numbers he’s posting might be okay for the average catcher, but Sanchez can do better. Here’s hoping that the home runs begin to pile up as the further removed he is from the biceps injury.