Michael King may have found his niche as a reliever

Right-handed pitcher Michael King has had an up-and-down season for New York. He made the team out of spring training and his early returns were excellent, as he gave up zero earned runs in April. But in May and June, his ERA was above 5.00, and due to a weird injury, he hit the injured list in early July with a finger contusion. It looked like it could possibly be another lost year for King, especially from a development standpoint.

However, upon returning to the team healthy and exclusively as a reliever on September 10th, King has looked absolutely dominant. Season-long, the splits are stark — as a starter, he’s recorded a 5.47 ERA with 20 strikeouts in 20.4 innings; as a reliever, his ERA is 1.57, with 39 strikeouts in 34.1 innings. His hard hit ball percentage as a starter was 37.2 percent; as a reliever, it’s 30.4 percent.

King would be far from the first baseball player to come up as a starting pitcher and get moved to the bullpen because his pitches play much better there. In particular, his average fastball and sinker velocity have definitely risen since returning earlier this month, and he’s now hitting 96 and 97 as opposed to 93 and 94. In the previous series against Texas, King was able to use both pitches at the very top and bottom of the strike zone to freeze the opposing batters for three called strikeouts (or, in the case of Charlie Culberson, to catch him staring right down the middle). His location to freeze Nick Solak was perfect, an unhittable strike.

Compare that sinker to this one from late May, which ended up a Lourdes Gurriel Jr. home run — the location is much less precise, and it stays high enough for Gurriel Jr. to muscle it out to center field.

Since returning, King has also entirely scrapped his slider and almost completely ditched his changeup, focusing instead on his four-seam fastball, sinker, and curveball. Interestingly, though he used it sparingly, the slider was an effective pitch for him, with a .225 batting average against, and it was his primary strikeout pitch when he was succeeding throughout April. Perhaps, as been discussed on the YES broadcast, simplifying his repertoire is a mental benefit as much as anything else, or maybe he’s concerned about the grip aggravating his finger injury.

Although used sporadically before his injury, King’s curveball also appears to be an improved pitch in his new role. Since returning, the 26-year-old hasn’t allowed any hits on a curveball, just one walk. Over half of the at-bats he’s ended with a curve have resulted in strikeouts. In fact, Baseball Savant has King in the 76th percentile of curveball spin. The one below to strike out Cleveland’s Myles Straw looks great — low in the zone, with a tight curve.

There’s no shame in giving up a home run to Shohei Ohtani, but in a late June start, King did just that on a curve that is clearly not as tight as the one above to strike out Straw.

The number of quality arms in the ‘pen seems to be expanding, and King could very well be called upon to record some key outs in middle relief. Further, if the right-hander can keep this success up, he could even be yet another late-inning option capable of going multiple innings for manager Aaron Boone.

And while former starters Luis Severino and Domingo Germán are currently with King in that role, both of them are almost certain to return to the starting rotation next season. King, on the other hand, looks like he could potentially be better served by staying the bullpen.