Trevor Plouffe was tested for concussion symptoms after he took a knee to the head Tuesday on a slide into second base.
"He got hit pretty hard," said Twins manager Ron Gardenhire. "They're doing the testing on him right now. He took a knee right to the head. We'll know more later." The Twins should provide an update on his status Wednesday.
Casey Fien struck out two in a perfect inning of relief Tuesday against the Braves.
The 28-year-old right-hander has a 4.19 ERA over 11 appearances. After getting pounded in limited run for the Tigers between 2009-2010, Fien has rejuvenated his career up north, posting a stingy 2.87 ERA and 1.01 WHIP over 56 games since the Twins called him up on the Fourth of July, 2012.

Glen Perkins blew his first save of the season in Tuesday's 5-4, extra-innings loss to the Braves.
Minnesota is having about as much success in Atlanta as they did during the 1991 World Series. Perkins was summoned in the ninth inning and recorded two quick outs before Evan Gattis blasted a 412-foot bomb over the left-field fence. The 30-year-old lefty remains a lighthouse in the dark night that is Minnesota's pitching corps. Perkins saved 16 games last year while registering a 2.56 ERA and now has eight saves, a 3.45 ERA, 0.96 WHIP and 25/5 K/BB rate over 16 appearances in 2013.
Trevor Plouffe left Tuesday's game in the 10th inning after taking a knee to the head.
Plouffe was sliding into second base to break up a double play when Dan Uggla's knee caught him in the head. The third baseman was able to walk off the field without assistance but appeared to be a little woozy. He'll no doubt undergo concussion tests.
Twins manager Ron Gardenhire said Tuesday that Samuel Deduno will be called up from Triple-A Rochester to start Friday's game against the Tigers.
In other words, Kyle Gibson's major league debut will have to wait. Deduno, who had a breakthrough performance during the World Baseball Classic, has a 2.70 ERA and 17/10 K/BB ratio in 16 2/3 innings over three starts with Triple-A Rochester since returning from a groin injury. He'll have a pretty tough first matchup, so fantasy owners should steer clear for now.
Twins recalled LHP Caleb Thielbar from Triple-A Rochester.
Thielbar, a member of the independent St. Paul Saints just a couple years ago, was sporting a cool 3.76 ERA and 34/8 K/BB ratio in 26 1/3 innings this season at the Triple-A level. He will serve as a middle reliever.
Kevin Correia surrendered five runs in four innings Monday in a loss to the Braves.
At least he'll always have April; Correia has seen his ERA jump from 2.23 to 3.90 while giving up 15 runs in 22 1/3 innings during May. He shouldn't have any fantasy value over the remainder of the season.