Junior tailback Derrick Coleman suffered an apparent neck injury and was carried off the field on a stretcher early in the third quarter.
Coleman lay face down for close to 10 minutes before his body was completely immobilized.
The injury came on an eight-yard gain, after he was struck in the head by Stanford's Owen Marecic. He fumbled on the play, but it was recovered by the Bruins.
He was taken to nearby Huntington Hospital for precautionary reasons. When he regained consciousness, Coleman had sensation in all of his extremities.
Coleman left with 23 yards on six carries. UCLA trailed Stanford 13-0 with just over 12 minutes remaining in the third quarter.