He was hit by a 93-mph fastball from Thomas in the sixth inning of Wednesday's 7-6 loss to the Red Sox, and stayed on the ground for a few minutes before walking off the field with the help of team trainers.
But team doctors ruled out a concussion, as he only suffered a black eye and a headache as a result of the pitch, which hit the bottom of his helmet.
"I had my bell rung," Parmelee said. "I was a little dazed when it happened but the concussion part never crossed my mind. But I did the testing and the docs said I'm doing real good. I'm feeling great."
Parmelee was out of the lineup against the Royals on Friday, as Twins manager Ron Gardenhire said he's still day to day.
"There's a little bit of swelling in his head, when he got hit, and little black eye, but he's actually OK," Gardenhire said. "He's out there running around, and doing pretty good. Just have to go day by day with him. Says he feels good. I'll let the doctors and trainers tell me."