Trainer Luca Cumani has ruled leading British contender Alkaased out of the Breeders' Cup Turf race at Belmont Park in America on Saturday.
Alkaased was rated a general 12-1 chance for the race
The five-year-old horse misses the 12-furlong contest after he was discovered to have a bad blood count.
"Alkaased will not be running," said Cumani. "His next race will be in Japan and there is a possibility of Hong Kong as well.
"It is a shame, but he probably would not have appreciated the ground."
Heavy rain had hammered the New York track on Tuesday, although a dry night meant some of the European challengers were able to work at the circuit.
Breeders' Cup Turf favourite Azamour, Juvenile entry Leo and Jack Sullivan, who contests the Classic, were among those in action.
Azamour was drawn in stall five, but Irish trainer John Oxx is more concerned about the going, which officials predict will be soft.
"The ground is really deep. It is not going to be easy," said Oxx.
Azamour's rivals will include the 2004 Turf winner Better Talk Now, one of four horses bidding for back-to-back Breeders' Cup wins.
English raider Ouija Board (Filly & Mare Turf), Ashado (Distaff) and Singletary (Mile) are the other returing champions.
Newmarket-based Cumani's hopes of a first Breeders' Cup win since Barathea in 1994 now lie with Queen Elizabeth II Stakes winner Starcraft, who is entered for the Mile.
A total of 101 horses have been entered for the eight Breeders' Cup races, with total prize money totalling more than $15m (£8.5m) for the 22nd running of the meeting.