Order Of St George (left): a best-priced 16-1 for the Arc

PICTURE: Patrick McCann (racingpost.com/photos)

RELATED LINKS:  Arc card and betting 

It will be Dettori’s 28th mount in Europe’s most valuable contest, which he won last year on Golden Horn, and follows his disappointment on Tuesday when his intended mount in the race, Fascinating Rock, was removed in favour of the Qipco Champion Stakes.

As well as Order Of St George, whose odds for the Chantilly showpiece range from 12-1 to 16-1, O’Brien is set to saddle general 7-1 third-favourite Found, the mount of Ryan Moore, and 25-1 chance Highland Reel, who will be ridden by Seamie Heffernan.

Quoted on his Ladbrokes blog, Dettori said: “I’m every bit as thrilled as I was when I rode Camelot in the race four years ago. I was getting a bit anxious that I might miss out after Fascinating Rock failed to make the race so I am delighted that Aidan has asked me to ride for him again.

“Everyone knows Aidan has had this race in mind for my horse for a while and the record of stayers in the race is good. His best form is probably over further but Marienbard had run in a Gold Cup the year before he went on to win the Arc for me so I know it can be done. I wouldn’t be too worried about the trip.

“Postponed is clearly the biggest threat. It’s difficult to see any flaws in the favourite but my horse is trained by a genius.”

Doyle to ride The Grey Gatsby

Another jockey securing a late call-up is James Doyle, who will partner The Grey Gatsby for the first time.

“James is one of the best around and we’re lucky to be in a position where we can use him,” said Adam Ryan, assistant trainer to his father Kevin. “The horse is bouncing at home and hopefully he can perform to his best.”

A field of 16 stood their ground at the latest forfeit stage on Thursday, with the Alain de Royer-Dupre-trained Zarak the only withdrawal. The final declaration stage is on Friday.