If he can work that in a little more often, he thinks, he can give opponents something to think about for a split second when they brace for the heater.
"That's what I want people to start talking about," Zumaya said. "Everybody knows I can throw hard. You can hear it when I come in. Everybody gets antsy to see that first pitch and look at the radar gun. I'd like people to know there's also a hammer at 85 miles per hour and [I] can throw it for strikes and it's dirty. And I have the capability to throw a hammer that's pretty good."
Not only did Zumaya lead the Majors in pitches thrown over 100 mph last year, nobody threw even a quarter as many triple-digit pitches as he did. Zumaya threw 233, according to the Bill James Handbook. Former Tigers Kyle Farnsworth threw the next most at 26. Tigers teammate Justin Verlander was third with 19. According to the same publication, Zumaya's fastball averaged 98.6 mph, more than two full miles per hour above any other Major Leaguer.
That's harder than he threw as a starter, of course, though he was an upper-90s pitcher in those situations, too. On the flip side, though, Zumaya had more variety then, especially with his curveball. He threw it last year, but he didn't throw it often, and usually in two-strike counts. He caught batters watching it on occasion for called third strikes, but he went away from it at times.
He thinks it can be more of a weapon.
"As a starter, that was my second-best pitch," he said. "But going from starter to reliever, I went with [a different] mentality. Yeah, I was throwing a little harder. I was throwing 97-98 [mph] as a starter, and now I got the opportunity to just rear back and throw it. And you lose the feel [for the other pitches].
"As a starter, you have to have feel for the pitches and know how to use them. Now I can go out there, and everybody knows I can throw 100 [mph] and above, so they're sitting on my fastball. And that's practically all I need is a fastball right now.
"But to pull out a curveball and show them I've got this, the word's going to get around that you don't only have a fastball [to worry about], but you have to watch out for that [curveball], too. It's something I've been working on and I want to master, because it's going to help my career in the future."
That has been his project this spring, and he believes that his curveball has been a big reason for his success thus far. He entered Saturday with five hits allowed and two walks in nine scoreless innings. The vast majority of his pitches have been fastballs, but he has mixed in his curve more than last year. They've accounted for at least a few of his 10 strikeouts.
Leyland thinks adrenaline, and learning how to channel it, has been a difference.
"He tries to throw it too hard," Leyland said of the old curveball earlier this month, "and a lot of times he just doesn't give it a chance to break because it's so hard. He doesn't give it a chance to work. But that's what Spring Training's for."
That's a factor behind Zumaya's offspeed pitch, too. It was a lower-80s mph changeup back then. Now, it's around 90 mph, but it's another option for him.
"It's a matter of me having the opportunity to come in and rear back for an inning or two," he said before throwing two innings of relief in a Minor League game on Saturday afternoon. "But it's a big difference when you look at it, 90 [mph] from 100 [mph] is still 10 miles per hour."
The combination would also give him a different look against left-handed hitters.
If he can polish those off, he'll look a little more like a starter. But that's as close to a starter as he'll get.
"Maybe he could've been a great starter, I don't know," Leyland said. "We think obviously we made the best decision, but is it necessarily the right decision? I don't know. He might've been a great starter."
That's not something Leyland ever plans on finding out.
"Someone else might," he said, "but I won't."