Stephens walked off the field in the ninth inning against the St. Louis Cardinals and appeared to be unhurt.
"He's aware and everything but he's going to have to go to the hospital and get some tests," Braves manager Brian Snitker said after his team's 11-4 victory. "It's always scary when you see somebody get hit in the head, the face. That's probably the most sickening thing you can witness in a game."
With one out and runners on second and third, Brendan Donovan blistered a line drive that struck Stephens in the right temple. The ball ricocheted into shallow right field for an RBI single.
Stephens never went down, but was immediately checked by the Atlanta training staff. After a moment, he walked off the field under his own power to loud applause from what remained of the crowd at Busch Stadium.
Tyler Matzek replaced Stephens and got the final two outs.