Quintero was at first base in the seventh inning, when Jarrod Dyson lined out to second baseman Robert Andino. Trying to double off Quintero, Andino's throw toward first hit Quintero in the ear flap of his batting helmet. Quintero put his hand up to his head as the ball bounced away.
After reaching second base safely, Quintero once again grabbed his head.
Manager Ned Yost and assistant athletic trainer Kyle Turner came out to check on Quintero at second base, and he remained in the game.
When the Royals took the field in the top of the eighth, Brayan Pena replaced Quintero behind home plate.
"We took him out kind of for precautionary reasons," Yost said. "He got a little dizzy when he got to second base, but he was fine. The umpire asked him, 'What day is it?' and he said Thursday right away. And he stumped me because I didn't even know what day it was. So he was doing better than I did. He's fine. We just ran him through all the precautionary tests and no side effects."
Quintero gave the Royals an early lead with a two-run double in the third.