Bob Baffert, winner of three Derbys, also got a jolt with Kafwain.
LOUISVILLE, Ky. (AP) -- Trainer Bobby Frankel believed Empire Maker's most dangerous work was done after the colt completed his final Kentucky Derby workout.
Turns out the expected favorite has a bruised foot, a minor injury that could change the outlook for Saturday's race, which has been unkind to favorites since 1980.
After returning from a 1-mile jog with stablemate Peace Rules on Tuesday, Empire Maker's injury was discovered. Frankel had a veterinarian examine the colt.
"My vet doesn't think it's a problem," said the Hall of Fame trainer, looking for his first Derby win. "He recommended I walk him another day. He thinks that will take care of it."
Jury still out
Frankel said Empire Maker will still run, but the odds could change dramatically when entries were made this morning. That's when Frankel expected to know more about his horse.
Until the bruise on Empire Maker's right front foot was disclosed, Churchill Downs oddsmaker Mike Battaglia was set to install the 3-year-old as the strong 6-5 favorite.
"Now I'll go by what Bobby says," Battaglia said. "If he says it's nothing to worry about, he'll stay there. If he says he'll run but there are some concerns, then I'll raise the line.
"And if he says he's out, I'll have to change everything."
Trainer Bob Baffert, winner of three Derbies in six years, also got a jolt.
Kafwain, one of his two entries, is out with a strained ligament in his right front leg following a workout. The colt won four of 11 starts and was third in the Santa Anita Derby on April 5, his last race.
That leaves Baffert, who won the Kentucky Derby with War Emblem last year, to saddle long shot Indian Express.
"I'm getting kind of excited about him," he said. "I feel good about leading him up there. He's only got one style, so we'll send him to the front and he'll go as far as he can."
Baffert lost his top Derby prospect in February, when 2-year-old champion Vindication was injured.
After Spectacular Bid won as the .60-1 favorite in 1979, only one other favorite -- Fusaichi Pegasus at 2.30-1 in 2000 -- has won.
In 1992, favorite A.P. Indy was scratched early on race day with a bruised foot. In 1996, Unbridled's Song finished fifth as the 3.50-1 favorite after being fitted with a special shoe to protect a bruised foot.
Still, Frankel was upbeat.
"You can never be 100 percent sure in this business, but I'd say I'm 98 percent sure he'll be all right," he said.
Empire Maker emerged as the leading 3-year-old after convincing wins in the Florida Derby and Wood Memorial. Frankel said the injury occurred following an earlier bruise to the same foot in the Wood at Aqueduct on April 12, a race run on a track drying out after a day of rain.
The bruise is under Empire Maker's shoe, part of which was filed away by a farrier so the foot could be soaked in hot water and Epsom salts.
Frankel also will saddle Peace Rules, who has won three consecutive races.