The injury, which he suffered on the bases Monday, isn't serious, and manager Brad Mills says he expects Schafer to start Wednesday afternoon's game.
"He's fine," Mills said. "Just as I was walking out here [to the dugout to meet the media pregame Tuesday], I heard he took swings in the cage and was fine. I thought it was a good day to give him a day off and get [Justin] Maxwell some at-bats. He hasn't had a start here in almost two weeks. We wanted to get him in there."
Schafer went 2-for-4 on Monday and has reached base in 23 consecutive games to start the season, which is two shy of Dennis Menke's club record of 25 set in 1969. Schafer was grimacing after stealing second base in the eighth inning Monday.
"When I went down to first base and I started leading off, I could feel my oblique was a little bit tight, and diving back into the bag, I felt something in the oblique," Schafer said. "It's still a bit tight today. Obviously, I want to play every day. If I can't help us win or I can't perform, it's not going to help us."