Gallo, who started at first base on Saturday, said he felt the hamstring tighten up on him when he doubled to right field with one out in the top of the third. He went to third on a passed ball and scored on a Robinson Chirinos home run that gave the Rangers an 8-2 lead.
At that point he was replaced on defense by Ronald Guzman.
"It's clearly frustrating to sit out, especially when you start the game," Gallo said. "But at the time we had a big lead."
Gallo had this problem last year, but was hoping an offseason of rest would address the situation. But it started flaring up on him in Spring Training. Gallo said he had an injection the second week of the season.
"It's nothing too serious," Gallo said. "I have been playing with it all season. I have been playing a lot the last couple of weeks and today, running on the double, it flared up pretty good."