Cavaliers rookie guard Kyrie Irving is being evaluated at the Cleveland Clinic as he recovers from a concussion.

Irving missed his first game of the season Wednesday night with the concussion. He was kept out after the team diagnosed him with the head injury, which he sustained Tuesday night in Miami when he was accidentally kneed in the head by the Heat's Dwyane Wade. Irving complained of a headache while warming up before Wednesday's game against the Los Angeles Clippers, Cavs coach Byron Scott said.

Irving remained in the locker room as his teammates won without him. Ramon Sessions started for Irving and scored a season-high 24 points with 13 assists.

There is no timetable for Irving's return.

The Cavaliers host Milwaukee on Friday and Philadelphia on Saturday.