Smith, a 6-10 freshman, hit his head on the floor while attempting to take a charge in the first half. He returned briefly, but missed a pair of free throws before scoring on an offensive rebound putback. He had four points and five rebounds in six minutes.
Smith will be re-evaluated Friday, at which time his status for Saturday's game against Stanford will be determined.
Peter Yoon covers the UCLA Bruins for ESPNLosAngeles.com.