Andreas Wohler's four-year-old Novellist has been ruled out of Sunday's Qatar Prix de l'Arc de Triomphe at Longchamp.
The King George VI And Queen Elizabeth Stakes winner will miss the event due to a temperature.
"He had a temperature this morning and it has developed even more, so there is no way we can let him travel to Paris," trainer Wohler told reporters on Saturday.
"It's unbelievable and very disappointing, but he has given us some great moments this year."
Novellist has won major races in Italy, France and Germany as well as in the United Kingdom.