Envisioning J.A. Happ’s role on the Yankees’ postseason roster

It’s pretty obvious that J.A. Happ has had a rough 2019 season. His ERA has spiked from 3.65 in 2018 to 5.10, his WHIP from 1.13 to 1.30 and his home runs from 27 to 32. Last year’s workhorse arm turned into a major liability, someone who stayed in the rotation only because other starters found themselves on the injured list. If not for that, a demotion probably would have been in order over the summer.

For much of the season, it would have been painful to suggest Happ has earned a spot on the postseason roster. However, try this stat from the YES Network’s Jack Curry on for size:

Yes, it’s a small sample size, but Happ has been mowing down lefties lately. It was prominent enough to get rival manager Alex Cora to comment about it, so there must be something there. Maybe Happ’s not effective enough to start a postseason game, but he might be just useful enough to come out of the bullpen.

Happ’s repertoire could serve him well as a reliever. He’s a fastball-first guy who rarely messes around with offspeed pitches. It’s unclear if he’d be able to adapt to the life of a reliever after starting almost his entire career, but I’m sure Happ would be willing to take on any role that involves him on the postseason roster at this point.

To further that point on Happ’s fastball, here’s more from YES statistician James Smyth:

Happ is at his best when he’s getting right-handed hitters to chase on his heater, and he’s been able to do that in his last handful of starts. He’s not throwing it harder or with more spin rate over that stretch, and there’s only a slight difference in his heatmaps:

The second one is concentrated a little bit higher and more on the corners, but it’s also not a drastic difference. The only other thing that looks different with Happ’s fastball is his release point. Both his horizontal and vertical release points have lowered, which may just be a coincidence, or it may be a catalyst for the increased whiffs.

The final hypothesis on Happ’s sharper fastball is part of a bigger picture. Happ has increased the use of his four-seamer and slider and lowered his usage of his sinker and changeup, which may just be a last-ditch effort by a pitcher to use more of his best pitches and less of his worse offerings. Whatever the reason, batters are whiffing more against Happ, and that’s put him back in the conversation for a postseason roster spot.

I think we can all agree that one good stretch from Happ after a season of inconsistency has not vaulted him back into the postseason rotation, but he could definitely snag a spot in the bullpen. Last year’s postseason lefty specialist was Stephen Tarpley, and that’s definitely a level that Happ can surpass when he’s right.

If the Yankees went with a postseason rotation of Tanaka-Paxton-Opener (featuring Severino)-German, Happ could still play a big role. If he continues to pitch like this, he might be a better option than a 38-year-old CC Sabathia with an ailing knee who has struggled with the long ball this year. The recent matchup numbers that Curry mentioned also hold up over a full season; Happ has been far better against lefties this season than righties.

I never thought I’d be saying this, but I’m intrigued with the idea of J.A. Happ as a postseason lefty specialist. There’s always one starter who succeeds out of the bullpen every playoffs (Madison Bumgarner, Nathan Eovaldi, 2000 David Cone vs. Mike Piazza). Why can’t Happ be this year’s success story?