LOUISVILLE, KY -- A minor ligament strain caused swelling in his left front ankle that forced I Want Revenge out of Saturday's Kentucky Derby, the first program favorite to be scratched the morning of the race in its 135-year history.

Dr. Foster Northrop, the attending veterinarian to first examined I Want Revenge, said this morning that the colt was headed to Rood & Riddle Equine Clinic in Lexington to have an MRI exam performed on Monday.

"It looks like he's got a very minor strain of his medial oblique semoidian ligament. It's just below the ankle," Northrop said. "It's a very important structure. They made a brilliant decision by not running this horse. They did right by the horse. It would have definitely hurt the horse to have run him."

A bone scan is also possible for Tuesday for I Want Revenge, who was unbeaten in two starts over conventional dirt since leaving the synthetic tracks of California, winning the Grade 3 Gotham and Grade 1 Wood Memorial.

"We want to cover all of our bases so we can have all the informantion we can get on this horse, because he is a nice horse," Northrop said. "It's a minor injury at this point."

Northrop did not believe the injury would stop I Want Revenge from racing again, but said, at best, the horse wouldn't go back to training for another 45 days.

"We know one problem. Does he have two problems? I don't know," he said. "And the severity, we're going to have a better idea tomorrow. From what I'm seeing it is not a career-ending injury because it was caught early and handled appropriately.

"He could race again this fall, absolutely. As of now it's as good of news as it could be."