Imperial Monarch and Nathaniel have been taken out at the latest forfeit stage for Sunday's Prix de l'Arc de Triomphe at Longchamp.
Trainer Aidan O'Brien had mentioned the Canadian International at Woodbine as being the long-term target for Imperial Monarch and that could well be his next port of call after a long absence from the racecourse.
O'Brien still has Camelot, St Nicholas Abbey, Robin Hood and Ernest Hemingway to choose from.
John Gosden's Nathaniel was ruled out of the race on Tuesday after being found to be running a temperature.
Sixteen horses remain in the all-aged middle-distance championship.
Saonois, the French Derby and Prix Niel winner, is expected to be supplemented on Thursday.