LOUISVILLE, Ky. -- Fusaichi Pegasus, the Kentucky Derby favorite, tossed an exercise rider and fell but was not injured during a morning workout Thursday at Churchill Downs.

Trainer Neil Drysdale said the Wood Memorial winner went through his daily morning trot without a hitch. But as he was being led off the track, the horse reared onto its hind legs just before reaching the draw gate off the track. The horse threw exercise rider Nuno Santos to the dirt, fell to the track and rolled over.

He got up within seconds, and Drysdale grabbed his bridle and calmed the colt. Drysdale led the horse off the track, and he calmly walked to his barn.

"He was doing superbly, and then he felt so good that he reared up and sat down," Drysdale said. "It startled him a bit."

The horse was not injured and Drysdale made light of the incident later.

"So far he hasn't put on a real show," Drysdale said. "When he's in California he can really do some tricks. We may be coming up to them this week. Some mornings he's a perfect gentleman; some mornings he's feeling so good he doesn't know what to do with himself."

The Kentucky Derby is May 6.