Detroit Tigers: The Unexpected Return of Michael Fulmer

The Detroit Tigers signed two starting pitchers in the off season, so Michael Fulmer moving to the bullpen felt inevitable. But that didn’t make his transition any less dispiriting.

Michael Fulmer was once one of the best young starting pitchers in baseball. But he missed all of 2019 with injuries, and he was undeniably bad when he returned in 2020 (8.78 ERA in 29.2 IP). He didn’t look any better as a starter this spring.

Detroit’s once-dominant starter seemed to be gone. His velocity was down, and his pitches lacked life.

But as soon as Fulmer moved into a relief role this spring he seemed to find himself again. And that success has carried over to the regular season. He has allowed two solo home runs in seven innings, but he hasn’t walked anyone and has 10 strikeouts.

It’s not unusual for former starters to move into the bullpen and succeed. With fewer innings to throw they tend to up their velocity a bit and winnow their offerings to focus on their best pitches.

Michael Fulmer Pitch Usage (Velocity in Parenthesis)

Michael Fulmer’s velocity HAS increased since last year, but clearly something else is going on, too. Fulmer has cut his fastball usage by more than 20% while increasing the usage of all three of his secondary offerings.

That’s the opposite of what we expect when a starter moves to the bullpen, and it feels like something influenced by A.J. Hinch and/or Chris Fetter.

And about that fastball velocity. Last year Rogelio did a deep dive on pitchers after Tommy John surgery, and found most saw an increase in velocity in their second year. Is that what’s going on here, or is Fulmer simply throwing harder in shorter outings?

Well, in his appearance against Cleveland last Friday, Fulmer threw 68 pitches over four innings. That’s his longest outing, by both innings and pitches, since September 2018. On Friday his fastball averaged 95.1 MPH in his first inning, 95.2 MPH in his second inning, 95.1 MPH in his third inning, and 94 MPH in his fourth inning.

He may have run out of gas a bit in his final frame, but Fulmer still hit 95 MPH, and his average fastball velocity was higher than it was in any outing in 2020. Fulmer hit 95 MPH just 12 times last year. He did it 13 times on Friday.

So what’s going on here? Just a month ago Michael Fulmer was admitting he couldn’t pitch like he once did:

"“Let’s be honest, I’m a different pitcher than what I was a few years ago,” Fulmer said. “There’s no denying that, and I’m trying to learn kind of on the fly. Just trying to learn sequencing and the ins and outs and ups and downs of different quadrants of the strike zone that I’m usually not working on.”"

Usually it takes pitchers months or years to adapt to a loss of velocity. Michael Fulmer couldn’t possibly have figured out how to be a better pitcher in less than a month, right? Well…

Michael Fulmer Changes Overnight

We have some evidence Michael Fulmer has changed as a pitcher. It seems unusual for a pitcher to change so quickly. Except we’ve seen Michael Fulmer do this once before.

Hop in a time machine with us back to 2016 and remember the results of Michael Fulmer’s first four big-league outings. They were all perfectly reasonable starts from a rookie, but he wasn’t exactly dominant. Here were his stats: 2-1, 19.1 IP, 6.52 ERA, 29H, 4HR, 22K, 9BB

Teams quickly realized Fulmer was mostly a two-pitch pitcher. Of the 379 pitches he threw in his first four starts, 233 (61.4%) were fastballs, and 117 were sliders (30.9%). He threw just 25 changeups.

Fulmer decided he needed a better changeup. So he worked on it between starts and broke it out in his fifth game. And it was awesome.

Fulmer threw 29 changeups in that outing against the Rays, setting what remains his career high with 11 strikeouts. He continued to use the change for the rest of the season and put together a string of dominant outings that propelled him to the Rookie of the Year Award.

So we have seen this sort of sudden improvement from Michael Fulmer before.

The Michael Fulmer Improvement Theory

We don’t know if this improvement is for real. Fulmer may go out and look like he did 2020, get shelled in his return to the rotation, and head right back to the bullpen when Spencer Turnbull rejoins the team.

But if he goes out and succeeds, we have a theory as to why it worked. We think the brief move to the bullpen may have removed a mental block for Fulmer.

It is completely understandable for a pitcher who had surgery on both his elbow and his knee to be a bit more hesitant while throwing. Fulmer knew his injuries were caused by the stress he put on his body, and in an effort to remain a starting pitcher he may have been holding himself back, consciously or unconsciously.

But as a reliever he was free to just go out and throw again. No worrying about conserving himself for later innings. Just back to trying to retire the man in the batter’s box. And suddenly he was throwing harder, and all his secondary pitches had more life.

Again, we don’t know if this will last as a starter. Michael Fulmer may go right back to trying to conserve energy and establish his fastball rather than use all his pitches. Only time will tell.

But if our theory is correct, and Fulmer’s foray into the bullpen has freed him, it could be a huge boon for the 2021 Detroit Tigers.