ANTE-POST favourite Teofilo will miss Saturday's Stan James 2,000 Guineas at Newmarket after suffering a setback.
Last season's champion two-year-old, trained in Ireland by Jim Bolger, was found to have some soreness atthe back of his off-fore knee.
The Galileo colt won all his five starts as a two-year-old, including the Group 1 National Stakes and the Dewhurst Stakes at Newmarket.
He was 2-1 favourite to begin his pursuit of Triple Crown glory with victory inthe 2,000 Guineas.
Bolger said in a statement: "Teofilo had a blow-out this morning at 6.30am over five furlongs and moved with his usual fluency".
"He gave every indication that he was fit and ready to run".
"Unfortunately at 9.00am there was excessive heat, and some soreness at the back of his off-fore knee when palpated".
"After discussions with my senior staff, I have decided that it would not be prudent to run him in Saturday's Stan James 2,000 Guineas".
"Consequently, I shall not be declaring him for the race".
"My staff and I have made every effort to have Teofilo fit and well for the first Classic of 2007 but must now accept that a cautious approach is the correct way to go as more serious damage could be done if subjectedto a race at this time".
"A further press release on his condition will be issued in two weeks."
Newmarket director of racing Michael Prosser expressed regret at the news of Teofilo's defection.
You you have got to have huge sympathy for the yard," he told At The Races.
"They have worked extremely hard to get him into the race and the vibes were superb".
"It's desperately unfortunate."
Neil Morrice, media and on-course representative for sponsors Stan James, added:"It is a blow to the racing world as a whole that Teofilo won't after all be able to defend his unbeaten record at Newmarket".
"We now have Adagio as a clear 3-1 favourite.Everything has gone to plan with Sir Michael Stoute's colt who looked in great shape under his big race partner Kerrin McEvoy on the Al Bahathri this morning."
Ladbrokes now make Adagio their 11-4 favourite and French raider US Ranger a 9-2 shot.
"We laid bundles at 5-2 during the past week and all the momentum was with Jim Bolger's colt," said spokesman David Williams.
"Coupled with Holy Roman Emperor's withdrawal earlier this year, it's the ultimate double-whammy".
"It's the most bitter of pills to swallow for ante-post punters".
"There's no way it can be dressed up any differently - the Teofilo news is horrendous."
Coral estimate Teofilo's late withdrawal will cost ante-post punters over ?million in lost stakes.
"This is undoubtedly the worst ante-post disaster for punters for decades both interms of the sums of money lost and the awful timing of the defection," said spokesman Simon Clare.
"Ante-post stakes on Teofilo at Coral were well into six figures and industry-wide, over ?million will have been wagered on Teofilo from last summerup until yesterday evening."