Forsythe said he felt the muscle tighten when he scored in the first inning (which he opened with a double) on Corey Seager's single.
"Didn't think too much of it, went back out for defense and felt a little tightness there," he said. "As the game went on, it didn't get any worse, I just couldn't get the tightness out of there. It wasn't a grab or pop or anything like that. My level of concern is not very high. We'll see what it feels like in the morning."
Forsythe also singled in the second inning and singled in a run in the fourth. When the fourth inning was over, Forsythe came out of the game as part of a double-switch.
Forsythe was replaced at second base by Enrique Hernandez, who moved over from left field.
Ken Gurnick has covered the Dodgers since 1989, and for MLB.com since 2001.