The setback is ill timed. It interrupts a hot streak where Quentin was hitting .371 with two home runs and five RBIs in his last 10 games.
He was evaluated in depth on Sunday afternoon by Padres lead physician Heinz Hoenecke, and the Padres believe the injury won't keep their cleanup hitter out for long.
"Carlos is a little banged up and we're keeping an eye on it," Padres manager Bud Black said. "He's day to day. We're cautiously optimistic that he's going to be fine."
Scott Bair is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.