Teofilo, last year's champion two-year-old and former ante-post favourite for the 2000 Guineas and Derby, has been retired from racing.
Teofilo (r) won last season's Dewhurst Stakes
The colt suffered a tendon problem shortly before the Guineas this spring and was ruled out of the race just 48 hours before it took place.
And trainer Jim Bolger has been unable to get Teofilo back in action.
"Following an unsatisfactory scan it has been decided to retire Teofilo from racing with immediate effect," he said.
Teofilo, the son of Galileo, charged through his juvenile career winning all five of his starts, which included the National Stakes and the Dewhurst.