LOUISVILLE, Ky. - Arkansas Derby winner Sir Cherokee was scratched from the Kentucky Derby on Friday due to a fracture in his right rear leg.

Trainer Mike Tomlinson discovered the injury Thursday evening, hours after the son of Cherokee Run galloped at the trackside training center, about five miles from Churchill Downs.

"He wasn't completely comfortable in his gallop,'' Tomlinson said. "We took a look at it, took an X-ray and found a small fracture in his right rear.

Tomlinson described the injury as minor.

"It's a bitter pill to swallow,'' Tomlinson said. "We were excited about his chances. It's disappointing and we will be back.''

The colt would have been Tomlinson's first Derby starter, and the first Derby mount for jockey Terry Thompson.

Sir Cherokee, who was 15-1 on the morning line, had the No. 3 post position.

As a result, the horses in the No. 1 and No. 2 posts -- Supah Blitz and Brancusi -- will be moved over one position, leaving the No. 1 post along the rail empty.

Sir Cherokee won the Arkansas Derby as a 55-to-1 long shot.