The Tigers said Zimmermann passed concussion protocol tests and was being taken for X-rays.
Making his third start of the season, Zimmermann retired Francisco Lindor on a fly ball starting the game. The 31-year-old right-hander had little time to react to Kipnis' liner on a 2-2 pitch.
"I tried," he said. "I saw it fine. I just had no chance of getting (the glove) up fast enough."
Zimmermann, who threw seven pitches, also posted a message saying that he's OK on his Twitter account Wednesday night.
Zimmermann was hit on the right side of his face in the first inning. The right-hander was face-down on the mound for several moments and then was attended to by head athletic trainer Doug Teter.
"It was terrifying and it made a terrible sound," Detroit manager Ron Gardenhire said. "Your heart drops. When you go out there you never know what you're going to see."
Zimmermann sat up and spoke to Tigers manager Ron Gardenhire, then walked off the field while holding a towel to his face.
The ball rolled to first baseman Miguel Cabrera, who stepped on first for the out. An obviously distraught Kipnis crossed the bag and knelt on the first base line as Zimmermann was examined.
An obviously distraught Kipnis crossed the bag and knelt on the first base line as Zimmermann was examined. Several Tigers' position players also knelt and the crowd of 10,872 went silent.
"You never want that," Kipnis said. "Everyone's out there competing. It was a scary moment, tough guy just to walk off like that. He's got a strong jaw."
Zimmermann, who passed the concussion protocol tests, has evidence of that. He had his jaw broken on a line drive while pitching in college. Doctors inserted 11 screws and several plates.
"I felt it," Zimmermann said. "I went down and just felt all my teeth were there, and my jaw wasn't peeled in like the first time it happened. So I think I got lucky. The first time I broke it back in college, they put a couple plates in there and the doc told me you'll never break it again. Put it to the test tonight and everything came back just fine."
Information from The Associated Press was used in this report.