Alex Cobb was taken off the field on a stretcher after he was hit on the right ear by a line drive on Saturday.
The ball was hit by Eric Hosmer in the fifth inning of a game between the Rays and Royals.
Trainers from both teams and other medical staff immediately ran onto the field. Cobb could be seen kicking his legs while being examined on the mound.
The Rays announced that Cobb remained conscious the whole time and was taken to Bayfront Medical Center in St. Petersburg for further examination.
Tampa Bay has only announced that Cobb has a concussion.
"Can't thank everyone enough for the prayers," Cobb tweeted Saturday night. "Was the only way for me to make it out of there ok. Look forward to getting back out there."