While trying to score from third on a sacrifice fly, Betancourt collided with Rangers catcher Matt Treanor.
"Yuni suffered a mild concussion [Tuesday] night, so we're going to give him a day or two [off], but he should be fine," Royals manager Ned Yost said. "He's feeling much better today. The dizziness and all that stuff is gone, but after a slight concussion, it's prudent to give them 48 hours."
Outfielder David DeJesus was also out of the starting lineup, after his wife Kim, delivered their first child Tuesday night. Willie Bloomquist filled in for DeJesus, making his fourth consecutive start.