Matthews collapsed on the field and needed help getting up before manager Mike Scioscia and a trainer walked him off the field. Matthews was taken to a hospital for X-rays, which were negative.
"It looked like he was slowing down to toss his helmet to Dino [Ebel, third-base coach] and he rolled his ankle," Scioscia told MLB.com. "Obviously, he was frustrated. I think he was surprised he got his shoe caught as he was trying to slow down.
"We've got some depth offensively, and hopefully Gary won't be out too much and we can keep the four guys together. They've been playing well for two weeks."
Third baseman Chone Figgins also made an early exit. Figgins left with a cramp in his left hand. Scioscia said if Figgins feels well Tuesday, he could get some at-bats against the Arizona Diamondbacks.
Information from The Associated Press contributed to this story.