Martin Dwyer suffered a nasty fall at Leicester when Red Lite jinked and unseated him when holding every chance in the second division of the Aston Flamville Fillies' Nursery.
Brian Meehan's filly was neck and neck with eventual winner Speedfit Girl before jinking sharply to her left, giving Derby-winning jockey Dwyer no chance of staying in the saddle.
His father-in-law, trainer William Muir, said: "They've taken him away on a board to hospital and put his head in a collar because obviously they are a bit worried about his neck.
"He's talking and he recognised me when I came over and he said his left arm was sore.
"He's off to hospital (Leicester Royal) and I'm going to go straight there now."
Muir added: "He didn't lose consciousness, which is a good thing and means he didn't bang his head. It looked more like he had damaged his collar bone, he knew everything and knew who the doctor was.
"The medical staff were very good with him.
"He'll go there and have X-rays and if everything is OK we'll take him home."