NEW YORK >> Things began unraveling for Triple Crown hopeful I’ll Have Another a day after the colt’s thrilling win in the Preakness three weeks ago.

A series of minor setbacks for the horse and his handlers culminated with the biggest shocker of all: I’ll Have Another’s sudden retirement on the eve of the Belmont Stakes with an injury to his left front tendon.

Friday’s news dealt further blows to a racing industry already battered by declining interest and yet another near-miss in the Triple Crown. The colt became the 12th horse whose Triple try was derailed since Affirmed swept the Kentucky Derby, Preakness and Belmont in 1978, and it occurred without I’ll Have Another ever reaching the starting gate.

“I’ve been hoping and praying he would stay injury-free, and it didn’t happen,” his trainer Doug O’Neill said.

I’ll Have Another won the Derby on May 5 and the Preakness two weeks later — both with stirring stretch drives — to set up the highly anticipated Belmont Stakes and a Triple try. Only 11 horses have won the Triple Crown and the wait for another now stretches to 35 years — the longest drought ever.

Now Saturday’s race is largely irrelevant to casual viewers who would have watched in the hopes of seeing history in the making. Dullahan, who ran third in the Derby, was installed as the new 9-5 favorite after I’ll Have Another was scratched.

The day’s highlight is likely to be I’ll Have Another, with jockey Mario Gutierrez aboard, leading the other Belmont horses to the starting gate in a wistful farewell.

“He’ll be my hero forever,” Gutierrez said. “What I’ll Have Another did for me is so amazing. He brought happiness to my life.”

But the colt and his camp had endured setbacks during the three weeks since the Preakness.

On his van ride to New York, the trip was delayed several hours because of traffic on the New Jersey Turnpike. A few days later, O’Neill was suspended 45 days and fined $15,000 by the California Horse Racing Board for a medication violation involving one of his horses in a 2010 race. His suspension is to begin next month.

Then, track stewards said that for the Belmont, I’ll Have Another would have to go without the nasal strip he wore in races this year, and exercise rider Jonny Garcia had visa problems and had to be replaced for several days.

The scariest thing was a near collision with a loose horse on the track last week, prompting racing officials to establish a special window of time for Belmont Stakes horses to be on the track.

Then the New York State Racing and Wagering Board ordered all the Belmont Stakes horses into a detention barn three days before the race. It was a security measure to ensure the race was run fairly, the board said, but the move angered some trainers, who were annoyed about relocating their horses to a new environment so soon before a major race.

“Some people have asked did the detention barn have anything to do with this. Absolutely not. Just a freakish thing,” O’Neill said about his colt’s injury.

O’Neill has been under intense scrutiny throughout the Triple Crown series because of his history of medication violations.

But he was never accused of doing anything illegal to I’ll Have Another, and the colt, along with the other 11 Belmont Stakes entries, all came back negative in testing done Wednesday by the state board.

O’Neill said I’ll Have Another was being retired because he developed swelling in his left front tendon that was the beginning of tendinitis.

“This is extremely tough for all of us. It’s far from tragic but it’s extremely disappointing,” he said.

O’Neill’s brother, Dennis, said it was hard to tell anything was wrong just by looking at the horse.

“He looks great. He’s sound. He went great this morning. He looks super (but) you just can’t take a chance,” he said. “He’s too valuable of a horse and we love him to death like all of them. You wouldn’t run a horse if you think something might happen.”

Doug O’Neill said he first noticed something might be wrong with the colt Thursday, hours after his usual morning gallop.

“We prayed he kind of hit himself and that it was a little bit of skin irritation,” he said as I’ll Have Another grazed in the grass behind him.

O’Neill had called an audible Friday and taken his horse out to gallop at 5:30 a.m., three hours earlier than he had been working out in the days leading up to the race. He wanted to avoid the congestion created by all the Belmont horses going to the track at the same time.

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

A veterinarian confirmed the diagnosis and suggested that O’Neill give the colt three to six months off before resuming training. But O’Neill said he and his brother, along with Reddam and his wife, were unanimous in deciding to retire the colt who had won four consecutive Grade 1 races, starting with the Santa Anita Derby in April.

“I really thought he was going to run off tomorrow and really show something,” Reddam said. “So we were all a bit shocked, but we have to do what’s best for the horse.