LOUISVILLE, Ky. — One-time Kentucky Derby favorite War Pass will miss next month's Run for the Roses because of a leg injury likely to sideline the colt for a few months.

Trainer Nick Zito said today that X-rays revealed a small fracture in the left front ankle of last year's champion 2-year-old.

"It's unfortunate _ it just wasn't meant to be, maybe," said Zito, a two-time winning Derby trainer. "It's a shame because he has all the ability in the world. He's one of the best I've ever had."

Zito said there was no swelling and the colt was "walking sound," but that he started to worry something was wrong with last year's Breeders' Cup Juvenile winner as pre-Derby workouts continued.

"We had some good days, but we started to get some bad days," Zito said. "We were getting to crunch time and I was getting these funny things, and I just couldn't get through it."

Zito said the fracture occurred recently and that a veterinarian suggested the colt probably injured the ankle in the Wood Memorial at Aqueduct, where War Pass finished second behind Tale of Ekati.

"The race took its toll, but when he got back to the barn ... he was great _ that's the heart he's got," Zito said.

War Pass, owned by Robert LaPenta, was unbeaten in four races in his championship campaign and had one win in three starts this year. The colt has earnings of $1.58 million and led all Derby contenders in graded earnings with $1.47 million.

Zito said equine surgeon Dr. Larry Bramlage would be consulted early next week. The trainer said it's too soon to know if surgery will be needed, but said the colt will likely be sidelined for a while.

"So what I've got to do is give him a few months off, see the healing process and go through all the motions," he said.

Zito said LaPenta was disappointed but took the bad news "as great as any owner could take it. He's grateful for having a champion _ and it could be worse."

Even with War Pass' injury, the Derby dream isn't over for Zito and LaPenta. They have another Derby contender in Cool Coal Man, winner of the Fountain of Youth at Gulfstream Park.

Another Zito-trained Derby hopeful is Anak Nakal, who won the Kentucky Jockey Club last fall at Churchill Downs.