The much-lauded racehorse will not compete for the Triple Crown Saturday, killing his chances at a Triple Crown because of an early tendon injury in his foreleg, his owner, trainer and the New York Racing Association confirmed.
"It's tough for all of us," trainer Doug O'Neill said in a press conference at Belmont Park Friday afternoon to announce the horse's sudden retirement. "We've had such an amazing run."
O'Neill added that the injury was "freakish," and that he didn't believe it had to do with his training Friday morning.
His owner, J. Paul Reddam, added that he didn't want to risk further injuring the colt.
"We're in shock, but we have to do what's best for the horse," Reddam said, adding that he wish he could have had an opportunity for I'll Have Another to "show his stuff" in Saturday's race.
"He's not lame. We could have run and compete, but it's not in his best interest."
I'll Have Another was set to attempt to become the first Triple Crown winner since Affirmed in 1978.
The Kentucky-bred chestnut colt won the Kentucky Derby and Preakness Stakes. He was the expert's pick to win Saturday's race with 4-5 odds as recently as Friday morning, before O'Neill announced the injury.
A deluge of comments from disappointed fans flooded Twitter.
"Terrible news about I'll Have Another - hope he's able to heal and lead a good, long life," Scott Swanay (@fantasy_sherpa) posted.
"Sad to see that I'll Have Another got scratched, I was pretty excited to see a Triple Crown winner" @JoshCullins added.
The colt is described as having speed, strength and stamina. His pedigree and training, combined with a fortunate post pick of position number 12 on the outside of the track, had experts predicting that he had the best chance of the dozen Belmont Stakes contenders to win the race.
I'll Have Another's health issues made headlines last week, after O'Neill announced that the colt would not be able to wear his nasal strips — equipment that he used to prevent bleeding from the lungs.
The horse had worn the strips during his wins at the Kentucky Derby and Preakness Stakes.