BERKELEY, Calif. — California tailback Jahvid Best was carted off the field Saturday night and taken to the emergency room after he landed on the back of his head when he leapt more than 5 feet in the air and flipped over a defender to score a touchdown.

Cal spokesman Herb Benenson said that a preliminary evaluation showed Best sustained a concussion, but more tests were being done before a final diagnosis would be announced by the school. Best had movement in all of his extremities, Benenson said.

Best's helmet came off on impact. He vaulted into the air over Oregon State safety Cameron Collins. Paramedics removed Best's jersey and he appeared to be receiving oxygen when taken away. Benenson said he was taken to an emergency room for observation and examination.

Best missed practice Tuesday and Wednesday with a slight concussion sustained in the team's 23-21 win at Arizona State last Saturday, but participated in full during Thursday's workout. The concussion wasn't diagnosed right away.

The latest injury — with 6:07 before halftime — silenced Memorial Stadium, where fans chanted "Jahvid! Jahvid!" before everything went quiet. His teammates went down on their knees and waited, then moved to the end zone as trainers and doctors took him away on a stretcher. The game was delayed 13 minutes.

Best, one of the most dynamic running backs in the country and a preseason Heisman Trophy contender, has 16 touchdowns and 867 rushing yards this season for the 23rd-ranked Golden Bears, including 29 yards on nine carries Saturday with the 7-yard TD run. He also has 22 catches for 213 yards.

Cal quarterback Kevin Riley took a hard hit with 1:19 left in the first half and was helped to the sideline.