California tailback Jahvid Best sustained a concussion and was taken to the emergency room after he leapt high into the air, flipped over a defender and landed on the back of his head in the end zone.

Best briefly lost consciousness following the terrifying fall from at least 5 feet, coach Jeff Tedford said after No. 23 Cal's 31-14 loss to Oregon State.

Tedford said initial tests had come back normal.

Best had movement in all of his extremities, Cal spokesman Herb Benenson said. Benenson also 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. Tedford didn't know whether Best would be kept in the hospital over night.

Best's helmet came off on impact. He vaulted into the air over Oregon State safety Cameron Collins on the 7-yard touchdown run. Best's jersey was removed and he was wearing an oxygen mask when carted out of the stadium. Benenson said Best 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.

Tedford said the fact Best has sustained two concussions in a week's span would be taken seriously.

"I'm sure that will be talked about," Tedford said. "He will be evaluated very closely, no question about it. There's no way we'd take a chance with any of our players."

The latest injury _ with 6:07 before halftime _ silenced Memorial Stadium, where fans chanted "Jahvid! Jahvid!" before everything went quiet. At least one family member was among those around the 20-year-old junior. Continued...