ELMONT, N.Y. — There was I'll Have Another at one end of the leather tether, looking every bit the wonder horse — his coat combed to a chestnut glow and his mane braided and glimmering.

At the other end was his trainer, Doug O'Neill, leading the colt out of Barn 2 at Belmont Park for a shockingly final bow before a battery of cameras Friday.

It was hardly the farewell anyone connected with the Kentucky Derby and Preakness winner — or, for that matter, anyone enamored of horse racing — envisioned.

The third act of the Triple Crown drama was supposed to play out Saturday in the 144th running of the Belmont Stakes, when I'll Have Another was going to try to become the 12th horse to sweep the U.S. classic races for 3-year-olds.

No rival dashed I'll Have Another's bid, but a sore tendon in his left foreleg did. The colt will not run in the 1 ½-mile Belmont. Indeed, he will not race again. Owner J. Paul Reddam decided to send I'll Have Another into potentially lucrative retirement as a stallion.

There has not been a Triple Crown winner since Affirmed in 1978; I'll Have Another is the 12th horse since Affirmed to win the Kentucky Derby and Preakness.

"I'm afraid history is going to have to wait for another day," Reddam said.

I'll Have Another's injury reportedly is minor, the equine equivalent of a sprained ankle, but it would have compromised the colt's chances.

"It's far from tragic, but it's extremely disappointing," O'Neill said.

The only horses to win the Kentucky Derby and Preakness who didn't compete in the Belmont are Bold Venture (1936) and Burgoo King (1932).

O'Neill over the years had compiled a lengthy record of medication violations involving his horses and was recently given a 45-day suspension by California authorities after one of his horses tested positive for a performance-enhancing substance.

New York officials and O'Neill moved quickly to try to eliminate suspicion surrounding the decision to scratch I'll Have Another. A spokesman for the New York State Racing and Wagering Board said all Belmont Stakes entrants were tested for prohibited substances Wednesday and all the tests came back negative.

O'Neill, whose prominent presence in the Triple Crown saga prompted state officials to enforce strict new monitoring protocols in an effort to prevent any chance at cheating, blamed bad luck.

"It's just a freakish thing," he said of the injury.

The trainer had been preparing I'll Have Another for the Belmont with regular and vigorous gallops rather than the more customary program of timed and more demanding workouts. Although the colt ran well Thursday morning, O'Neill said he was a little off in the afternoon.

"We noticed some loss of definition in his left-front leg," O'Neill said. "Like every other owner and trainer, we prayed he just kind of hit himself and it was just a little bit of skin irritation. We did him up in a special poultice."

On Friday morning, O'Neill changed the colt's routine and sent him out to gallop easily at 5:30 a.m., three hours earlier than usual.

"I thought he looked great on the track," he said. "Then cooling out, you could tell that swelling was back and at that point I didn't feel very good."

Veterinarian James Hunt examined I'll Have Another, gave him an ultrasound and ultimately diagnosed the onset of tendonitis.

"It's like if you had a sprained ankle; you could loosen it up and go play basketball, but it would hurt more and get worse the following day," said Dr. Larry Bramlage, a noted equine surgeon. "If I'll Have Another was a gelding, you'd give him the rest and bring him back. But he's the Derby and Preakness winner with a valuable second career as a stallion."

Reddam said, "It wasn't like he had an injury and Doug took him out for a test drive this morning."

While I'll Have Another's pedigree is more blue collar than blueblood and he is a small colt, his 5-for-7 race record means he could fetch anywhere from $7 million to $9 million as a stallion prospect, according to a commercial breeder who was granted anonymity because he might bid on the colt. If I'll Have Another had captured the Triple Crown, his value at stud might have doubled.

"We've got to do what's best for the horse," Reddam said. "He can't compete at the top level. He's done enough."

Dale Romans, the trainer of Dullahan — who is a 9-5 favorite on the revised morning line to prevail Saturday — said, "This was going to be a special race, one of the biggest races of our time. I'd rather have him (I'll Have Another) in there. It would have been something special to beat him."

Romans has been a critic of the requirement to move the Belmont entrants to the same security barn earlier in the week.

"The detention barn is bad," Romans told the Herald-Leader of Lexington, Ky. "I don't know if it played a role or not (in I'll Have Another's injury) but we're always going to wonder.

"Whoever came up with this idea should resign."

The three weeks between the Preakness and the Belmont can seem an eternity, especially for those fortunate few horsemen whose charges are running for an elusive piece of racing history.

So much can go wrong.

In 1979, the brilliant Spectacular Bid stepped on a pin the morning of the race and that, along with a poor ride by Ronnie Franklin, helped undo his championship bid.

All week, O'Neill spoke of how quickly good fortune could turn to bad when it came to horses.

On Tuesday, he made a visit to St. Patrick's Cathedral and lit some candles in the hope of divine intervention.

There was perhaps no one more crushed by the day's events than the colt's rider, Mario Gutierrez. In January, he was a relatively unknown rider from Hastings in Vancouver, B.C., seeking mounts in Southern California.

But over the past several weeks, he had become among the most satisfying feel-good stories in all of sports.

In an effort perhaps to draw a bigger crowd to the racetrack on Long Island and conjure a little bit of magic for the sport from a wrenching turn of events, Gutierrez and I'll Have Another will lead the remaining 11 Belmont horses in the post parade.

It is hardly the same as leading the colt back to the winner's circle and a permanent place in the pantheon of the sport's greats, but Gutierrez understands he has much for which to be grateful.

"What I'll Have Another did for me is amazing," he said. "He changed my life. He'll be my hero forever."