Connections admit it was a difficult decision to favour ParisLongchamp over another trip to the UK for the Champion Stakes at Ascot.
The Prix du Jockey Club champion will be trying 12 furlongs for the first time when he tackles Europe's richest middle-distance contest and Jean-Claude Rouget's son of Churchill will arrive in the French capital with a small point to prove having finished third when sent off favourite for the Irish Champion Stakes at Leopardstown.
However, both Rouget and regular pilot Christophe Soumillon believe their Chantilly and Eclipse hero can defy the nagging stamina doubts, while only a repeat of last year's heavy ground would see the colt rerouted.
"It wasn't an easy decision to run in the Arc rather than the Champion Stakes, but we looked at both races properly," said Georges Rimaud, racing manager for owner the Aga Khan.
"He was beaten in the Irish Champion but after it we all got together and discussed it. Both the trainer and jockey think there is a good chance he will stay the trip. There may be a question mark about it but we feel he can do it.
"If we didn't think he would stay we wouldn't go, we think it's worth trying.
"Should the ground be extreme, we may reconsider running but soft ground wouldn't be a problem."
Meanwhile Rene Piechulek is looking to make history as he bids to ride back-to-back Arc winners.
Last year, Piechulek was aboard Torquator Tasso as the German-trained runner caused a huge shock and this time around he will be riding another outsider as he partners the defending champion's Baden-Baden conqueror Mendocino, who is trained by his partner Sarah Steinberg.
Last year's success in Paris was a breakthrough moment for 35-year-old, but he believes winning aboard a horse trained by Steinberg would eclipse that achievement.
"It would be very very special," said Piechulek. "It was amazing that I was on board at Baden-Baden when Sarah won her first Group One and if we were to win on Sunday, it would be another day in the history books.
"I don't think there has been a trainer and jockey who have won the Arc, who have also been partners, so that would be something very special."
Reflecting on 12 months ago, he added: "It took a while before I realised I had not only ridden in the Arc, but actually won it. But I'm really looking forward to riding in it again, it is quite something."
Following his Arc win, Piechulek signed a retainer with Mendocino's owner Hans-Gerd Wernicke who runs his horses under the Stall Salzburg banner. Although the result of that contract is the loss of the ride on the defending champion, who will be partnered by Frankie Dettori this time around, he believes he did what was best for his career.
"Last year following the Arc I was offered a contract as retained jockey and it made sense to take that contract," Piechulek continued. "It was clear then that I wasn't going to ride Torquator Tasso.
"Obviously he is a horse I would have loved to have ridden again because we have written history together, but this is part of my contract and I respect my contract."
Mendocino booked his ticket for the Arc by defeating Torquator Tasso by a head in the Grosser Preis von Baden earlier this month.
"If I had to compare them, the one thing that unites them is they both want soft ground and both want a calm race. Tasso in my opinion needs longer to accelerate, while Mendocino has a turn of foot which lasts a bit longer in the straight," said Piechulek.
"Mendocino is not the same type as Torquator Tasso. Last year we put Torquator Tasso on the outside as we knew he needed a long time to get rolling. Mendocino can come between horses and his turn of foot allows him to be a bit quicker out of that position.
"In Baden-Baden there was a lot less starters, so it was a different kettle of fish (to an Arc). But the horse has been very satisfying since and hasn't gone backwards luckily. I'm going to Paris with a positive feeling."
The rider also feels Adayar's absence in the 12-furlong contest increases Mendocino's chances of causing an upset in the race, while he refuses to rule out his old ally going back-to-back in Europe's most famous all-age contest.
He said: "I think you have to fear many of the horses in the race. I have read in the press this morning that Adayar isn't going to the start. He is a horse I respect a lot and saw in the race last year. So with him being out. I will need to look again.
"Obviously Tasso, I can tell you I'm not going to lose sight of him and I also respect the French horse Vadeni."
Along with Adayar, the Ger Lyons-trained Thunder Kiss and Jim Bolger's Mac Swiney were taken out on Tuesday meaning 24 remain. Verry Elleegant is expected to be supplemented on Wednesday at a cost of €120,000 but only 20 horses are guaranteed a run, with the Australian star currently number 22 on France Galop's elimination order