Hawk Flyer, a leading fancy for the Seabiscuit St Leger, has been put down after fracturing a pastern.
The three-year-old colt, trained by Sir Michael Stoute, was as low as 6-1 for the final Classic of the season at Doncaster on Saturday after finishing third in both the Peugeot Gordon Stakes at Goodwood and the Daily Telegraph Great Voltigeur Stakes at York.
“He has shattered his pastern very, very badly and had to be put down,” said Joe Mercer, racing manager to owner Saeed Suhail.
The owner and trainer had been seeking their second Classic success of the season following Kris Kin’s victory in the Vodafone Derby at Epsom in June.
Hawk Flyer, a son of Silver Hawk, made his racecourse debut just one week after his stablemate’s memorable triumph in the premier Classic.
After finishing second on his debut at York, he won his next two races at Doncaster and Ascot before his fine efforts in two recognised Leger trials.
Stoute now does not have a runner in the one British Classic that he has yet to win and Frankie Dettori, who was to have ridden Hawk Flyer, is now left without a mount.
Following the news, Ladbrokes have cut ante-post favourite Brian Boru to 7-4 from 2-1.