Kiermaier suffered two metacarpal fractures in his left hand, while the Rays took a 5-4 loss to the Tigers on Saturday afternoon at Comerica Park. The club will recall outfielder Mikie Mahtook from Triple-A Durham on Sunday to replace Kiermaier on the roster.
"Just kind of quieted our whole dugout," Rays manager Kevin Cash said. "I think everyone knows the kind of energy he brings to the team on a daily basis, so we'll kind of have to work together to get through that a little bit.
"... It's a big loss. But the guys in this clubhouse carry themselves really well. They'll kind of rally around each other and pick each other up. K.K. is a huge part of what we're doing, and when he gets back, he'll be right back in there. In the meantime, guys will adjust. ... We'll be fine."
How long Kiermaier will be out is yet to be determined. The Gold and Platinum Glove center fielder will fly to St. Petersburg on Sunday and be re-evaluated on Monday by Dr. Douglas Carlan, the team's hand and wrist consultant.
"They just said [it's a] good thing it's not my wrist," Kiermaier said. "That was the good news-bad news. Bad news, I broke my hand, but the good news, it wasn't the wrist. Because that's a lot more serious."
Cameron Maybin had just led off the Tigers' half of the fifth with a single and took off to steal second when James McCann hit a Texas Leaguer to center field. The ball looked uncatchable, but as Maybin neared second base, Kiermaier closed on the ball. He dove at the last second and appeared at first to have made the catch.
"I knew he was stealing," said Kiermaier, who was thinking he might be able to double him off. "I got a good jump on the ball. I got there. It's a play I've made many times before where I've avoided [getting injured]."
Evan Longoria was asked how big of a blow losing Kiermaier was, particularly after recently losing Logan Forsythe as well.
"The guy led the league by a ton in WAR last year," Longoria said. "A huge part of our team. A huge part of the clubhouse morale and everything. Losing Logan was big, and now this.
"We'll have to kind of regroup tomorrow and overcome. We've had some tough situations over the years. I feel like we have the guys in here to do it. We have the mindset. We'll just need some different guys to step up and get some contribution from top down. But it's a tough blow."
Kiermaier's loss was even felt in the Tigers' clubhouse.
"It was awful," Tigers manager Brad Ausmus said. "He plays the game the right way. You could tell as soon as he dove for the ball that something bad happened. He's the type of guy, because of the way he plays, you want to see him succeed.
"I don't want to see him succeed against us, necessarily, but you want to see him succeed overall, because he seems like the type of kid that is always hustling, wants to win and goes about his business."