Dallas forward Dirk Nowitzki left the Mavericks' game against Philadelphia on Wednesday night after straining his back.

Nowitzki grimaced as left the court late in the second quarter and soon after went for treatment in the locker room. He did not return for the start of the third quarter. There was no immediate word on whether he'd return in the second half.

Nowitzki scored 14 points on 5-for-8 shooting in the first half, and has averaged 26 points and 9.7 rebounds in three games.