I'll Have Another Has Tendonitis, Scratched on Eve of Historic Triple Crown Run

June 8, 2012 -- Sports fans were shocked today as I'll Have Another was scratched from the Belmont Stakes on the eve of his historic run for the triple crown.

Owner J. Paul Reddam and trainer Doug O'Neill said they had decided to retire the horse from racing after it became known this morning that the 3-year-old colt had the beginnings of tendonitis in his left front tendon.

I'll Have Another was physically capable of competing on Saturday, Reddam and O'Neill said, but it would not have been in the horse's best interest.

"We have to do what's best for the horse, and if he can't compete at the top level he's done enough," said Reddam during today's press conference. "I'm afraid history is going to have to wait for another day."

"It's extremely disappointing, and I feel so sorry for the whole team," O'Neill said. "We've had such an amazing run."

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The horse's withdrawal from the Belmont Stakes sucks much of the excitement out of the race, which was expected to draw 100,000 people to the New York track and millions more to their TV sets. I'll Have Another would have been competing to become the first Thoroughbred in 34 years to capture the triple crown. Affirmed was the last horse to win it in 1978.

Instead, I'll Have Another now becomes only the third horse to win both the Derby and the Preakness and not compete at Belmont. Bold Venture did not particpate in 1936 and Burgoo King skipped the race in 1932.

ESPN reporter Jeannine Edwards told ABC News O'Neill ran I'll Have Another at 5:30 a.m. ET under the cover of darkness, something he had never done before. O'Neill had been training the horse at 8:30 a.m. ET at a strong gallop, but this morning the horse was moving at an easy cantor.

O'Neill said he took the horse early to avoid congestion, and Reddam added, "It wasn't like he had an injury and Doug took him out for a test drive. It was nothing like that."

O'Neill called I'll Have Another's injury a "freakish thing."

Edwards told ABC News that last minute injuries were not uncommon in horse racing, and after observing I'll Have Another during training runs she is not surprised.

"I had watched the horse train over the last few days, and he didn't seem to be moving with the same efficiency, energy and enthusiasm as we had seen from him before the (Kentucky) Derby and the Preakness," she said.

The news comes after a tumultuous week at Belmont where the race was almost canceled because of a labor strike. A tentative deal ended the strike threat.

Known as the "test of a champion," the Belmont's length is what makes it daunting. The track is 1½ miles long, while the Derby is 1¼ miles and the Preakness is 1 1/8 miles.

I'll Have Another's improbable run has now come to an unexpected end. The horse was sold as a yearling in 2010 for $11,000 and faced 15-to-1 odds in the derby before becaming the first winner ever to have started from post No. 19.

I'll Have Another is scheduled to return home to California on Sunday or Monday.

The Associated Press and ESPN contributed to this report.