"We'll find out tomorrow. We'll see when I wake up," Gonzalez said after the game. "It wasn't the best slide. I kind of slid over top of my other leg."
Gonzalez, who has a Major League-leading 32 walks in June, suffered the injury as he slid into third base with a triple in the fourth inning.
Gonzalez remained in the game a few pitches before being attended to by Padres head trainer Todd Hutcheson and manager Bud Black.
Gonzalez, who is hitting .271 with 24 home runs and 47 RBIs this season, didn't appear to slide awkwardly on the play.
He was replaced on the bases and later at first base by rookie Kyle Blanks.
"It's too soon to tell," said Black. "We'll see how it resolves over night. There's some soreness. He tweaked some muscles around the knee. We'll see how it sets up over night."
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.