Jockey Mario Gutierrez was taken to a local hospital after being unseated from Queen Stormborn in the ninth race at Del Mar on Friday.
Queen Stormborn, racing in a $50,000 claimer for maidens at five furlongs on turf, was disputing the pace when she appeared to be startled and struck the inside temporary rail. Gutierrez was unseated in the incident. The filly continued running around the racetrack.
Gutierrez was given attention by paramedics on the track before being transported to the hospital for further evaluation, a track official said.
Queen Stormborn was not injured, trainer George Papaprodromou said.