Mitchel Oldenburg of the Beta Factory Team suffered a crash during qualifying for the AMA Supercross in San Diego on Saturday, sustaining multiple injuries.
In addition to a concussion, Oldenburg fractured both his ulna and radius in his arm. He has since undergone surgery, but the injuries will keep him sidelined for the foreseeable future.
Misfortune continues for the Beta team, as Benny Bloss was already forced out with an injury during the opening round in Anaheim.
