What the heck is going on with Tommy Kahnle?

For years now, the strength of the Yankees’ bullpen has been one of their calling cards. This season, though, one of the more curious examples of Yankee bullpen development has been Tommy Kahnle. After entering 2018 slated to be one of the Yankees’ primary set-up men, Kahnle has hardly been heard from.

Kahnle was drafted in 2010, spent three seasons in the low minors before being plucked away in the Rule V draft, and traded to the White Sox at the end of the 2015 season. From there he found himself as a reliever, with a solid 2016 and an outstanding 2017.

His breakout last season made him a prime target for Brian Cashman as the Yankees loaded up for last season’s playoff run. Kahnle probably had the most pure value of the three players traded from the South Side, as he was having a better season than David Robertson and carried more team control, being arbitration eligible for the first time in 2019.

Since then, the bizarre tale of Tommy Kahnle has taken a couple unfortunate turns. He wasn’t quite as good post-trade as he was in Chicago last season, pitching ten more innings before the trade and seeing a dip in performance in the Bronx:

Still, though. Kahnle was pitching at what’s pretty much the upper limit possible for bullpen arms, it wasn’t surprising to see a bit of a drop-off in his numbers once he moved to the Bronx. Add in the fact that the AL East is a much tougher division than the AL Central, I cut him a lot of slack and was excited to see what he could do in 2018.

And then it got worse.

In 2018, Kahnle has been the worst pitcher in the Yankee bullpen, for the times when he’s been in it at all. A 7.00 ERA is terrifying, but his 5.68 FIP and ballooning walk rate show that his performance was probably more than pure bad luck. There are real process concerns with him.

After being optioned to Triple-A Scranton, Kahnle’s been outstanding. Again, this isn’t necessarily surprising, given that an MLB-caliber player should do well when going up against MiLB competition. He’s halved his walk rate while bumping up his strikeouts, posting a 1.93 ERA and 2.38 FIP.

It looks like Kahnle has fixed some of his process concerns, but the biggest problem he’s faced in 2018 is a drop in velo:

While with Scranton, Kahnle’s velocity hasn’t budged, stuck around 94-95 mph rather than the 97+ he was managing last season. This is especially concerning as Kahnle had battled shoulder tendinitis earlier in the season, and many hoped that was the cause of the velocity drop. If you’re already struggling with command, like Kahnle has this season, a loss in pitch speed is a nightmare, as it shortens your margin for error on pitches in the strike zone.

I think the Yankees still see something wrong with Kahnle, physically or mechanically. He’s been healthy for both doubleheaders the Yankees have played in the last couple weeks and wasn’t selected as the 26th man for either. David Hale has been purchased from the minors in lieu of the option-able Kahnle.

Relievers are, by nature, the most volatile of positions. It’s not uncommon to have a relief ace one year suddenly disappear. Still, you’d expect a player of Kahnle’s age, coming off what seemed like pretty sustainable success last season, to carry it over to some degree, right? Something’s still up with Tommy, and it casts a shadow on what should be a shining star in the Yankee bullpen.