The participation of the Irish and Yorkshire Oaks winner had been strongly mooted since her win at York, but trainer William Haggas had always said the decision would be down to the ground.
Traditionally the Arc has taken place on ground with plenty of cut in it, but with a lack of any appreciable rain in Paris of late, the surface looks like being in her favour.
Emmanuel Roussel, from the communications department of France Galop, said on Wednesday morning: “It is very difficult to predict what the ground will be like at the weekend so far in advance given the changing weather forecasts.
“There is a bit of rain forecast on Saturday and Sunday, and there’s a bit of drizzle around today but nothing major.
“Before Saturday it is set to be windy and chilly, but with no rain.
“Currently the going is around 3.3 (penetrometer reading), that equates to around good/good to soft and that is what we are aiming for.
“It was watered yesterday (Tuesday), around five millimetres was put on, and it will be watered again but nothing major, we will not try to turn the ground soft.
“It is difficult when rain is forecast to know how much watering to do, the forecasts change regularly.”
If the ground is good to soft that may raise the hopes of Cracksman taking on stablemate and last year’s winner Enable, with both of John Gosden’s big guns still among the 20 possibles for the middle-distance championship.
Aidan O’Brien can call on St Leger victors Kew Gardens and Capri, along with Hunting Horn, Nelson and Magical.
Salouen is on the verge of achieving a long-held ambition of owner Rohan Balasuriya when he runs in the showpiece.
Sylvester Kirk’s consistent four-year-old has kept top company for the past two seasons, coming up agonisingly short on several occasions.
His best effort was when beaten just a head by Cracksman in the Coronation Cup at Epsom in June, and he has since proved that was no fluke with two big runs in France.
“He’s in great form, we’re happy with him and we’re looking forward to Sunday,” Kirk said. “His owner has always dreamt of running him in the Arc, so we’ve always tried to get him there and we are lucky enough to do that.
“I would have preferred a little bit of cut in the ground, like we had at Epsom, although he broke a track record at Windsor as a two-year-old on very fast ground.”
He added: “He’s struggled to win because he’s been in top company. It might not have done him any harm dropping in class to try to get his head in front, but not having those races in between those Group Ones has probably helped him run so well in them.
“We’ll probably pop him out and hope he makes it into the first half dozen, we’ll have a chat with the owner and come up with a plan.”
Click here for a runner-by-runner guide to the Arc
Click here for the latest on hot favourite Enable.