The Idol runner-up, 22, was injured Tuesday night when she tripped backstage before a concert at Bobcats Arena in Charlotte, N.C., the New York Post reports.
McPhee went on with the show, singing two songs while wearing slippers. X-rays taken at a hospital afterward revealed a hairline fracture in her left foot, the Post says.
In spite of the injury, McPhee will stay on the "Idols Live" tour. "She's in discomfort, but she's fine," said Roger Widynowski, a rep for McPhee's record label, RCA. "She will continue on the tour and is not defaulting."
Although the tour kicked off on July 6, McPhee missed the first three weeks, citing doctors' orders not to sing while she was sick. She was scheduled to perform with her fellow Idol finalists for the first time on July 27 in Pittsburgh, but her flight was cancelled due to bad weather.