Buckley, 40, was galloping a Thoroughbred trained by Asmussen when he was thrown from the horse and hit the left side of his head. Immediate medical care was delayed slightly due to a wait for the ambulance, which had been on the main track side.
Following an on-track examination, the rider was transported to Saratoga Hospital, where a CT scan revealed blood on the brain. Buckley was then flown to Albany Medical Center around 8:00 a.m., where he began to lose movement on his right side. Following another CT scan performed around 12:30 p.m., he took a turn for the worse and had to be revived, Asmussen told the Daily Racing Form.
Buckley had ridden at Finger Lakes but was not active as a jockey this year. He has worked for Asmussen for about 16 months, the trainer said.