"When he had his mechanics right, I think the life was on there," Ausmus said before Wednesday's game against the Twins. "The breaking balls had more depth and there was more life on the fastball."
Zimmermann, for his part, felt encouraged.
"On Saturday, I was really, really rushing. I was really fast [in delivery to the plate]," Zimmermann said. "I didn't lift my leg up all the way and I was rushing to home plate. Today, I slowed myself down and I was able to rotate and stay behind the ball better."
The radar gun wasn't on at Comerica Park for the sim game, so there were no numbers on velocity. However, no hitter seemed to square up a ball with a swing, popping up several while pounding others into the ground. Machado, Steven Moya, JaCoby Jones took all but one of the at-bats, with Nick Castellanos stepping in for an early appearance against Zimmermann before grounding meekly to second.
Zimmermann threw 80 pitches, spread out over four innings. Fellow Tigers pitchers Justin Verlander, Michael Fulmer, Mike Pelfrey and Mark Lowe served as his infielders, even lining up to slap hands with Zimmermann when he was done to simulate the end of a real game.
"I threw a lot of good [pitches]," Zimmermann said, "way more good ones than bad ones. So that's a good sign. I feel good; that's the main thing."
The earliest Zimmermann would return is next week at Minnesota. Fulmer, Verlander and Daniel Norris are scheduled to start this weekend at Cleveland in what likely amounts to a must-win showdown for any hopes the Tigers might harbor for an American League Central title. But with a deficit in the AL Wild Card race as well, and several teams in the hunt, every game is critical.
That's what the Tigers have to weigh as they try to negotiate Zimmermann's situation. Ausmus has committed to three more regular-season starts for Fulmer, including Friday, which all but rules out the previous thought that Zimmermann might allow the club to skip Fulmer for a turn in order to conserve the rookie's innings.
Add in Verlander, Norris and Matt Boyd, and the Tigers have five starters already, not counting Mike Pelfrey's spot start on Thursday. The performance of youngsters Fulmer, Norris and Boyd has allowed Ausmus to stay guarded about Zimmermann.
"Fulmer has pitched outstanding, and Boyd and Norris have pitched really well," Ausmus said. "Would you rather have Zimmermann for 34-35 starts? Absolutely. But these guys have stepped up and done a nice job. To me, that's the crux of why we're in the race, because those guys have pitched well."