The Yankees are without one of their most productive hitters, as Gardner was hitting .269 with 16 home runs, 56 RBIs and 19 stolen bases entering Sunday and had moved into the No. 3 spot in the lineup recently.
He did say that he felt better than he did on Saturday, but still felt as if the injury could get worse by playing.
"I'm not exactly sure what it is, but just the way it feels, it feels like it could [get worse]," Gardner said. "I just don't know what to expect at this point."
David Phelps (right elbow inflammation) felt good after throwing a 31-pitch simulated game on Sunday. The Yankees have not informed him of what his next step will be as he tries to return to the bullpen to help the team down the stretch.
Jamal Collier is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.