Massaat made a triumphant return after a year off the track when winning the Hungerford Stakes at Newbury last month. Runner-up in the 2000 Guineas last season, the Owen Burrows-trained four-year-old gets another chance at a Group One over a mile.
The Jean-Claude Rouget-trained Taareef looked very good with victories over Zelzal and Al Wukair in two Group Three races during the summer and connections blamed the pedestrian pace for his defeat in the Prix Jacques le Marois on his latest start.
"The plan is to run both," said Sheikh Hamdan's racing manager Angus Gold.
"Owen has been very happy with Massaat. It's the obvious progression and will tell us a bit more.Massaat will appreciate the rain-softened going at Chantilly on Sunday (PA)
"Things didn't work out for Taareef in the Jacques le Marois. They went a slow pace and sprinted which didn't suit him."
Harry Dunlop reports French regular Robin Of Navan to be ready to drop back to a mile after being well-beaten in the Grand Prix de Saint-Cloud over a mile and a half two months ago.
"The plan is to run. We're keen to try the mile," said the Lambourn handler.
"The ground is on the softer side at the moment. They had some rain over the weekend. I think it's going to be dry for the rest of the week and then a dampish weekend, so I think it would be on the easy side.
"He shouldn't mind that too much."
Godolphin, who own the multiple Group One winner, have a second string to their bow in Marois runner-up Inns Of Court, trained by Andre Fabre. The latter has also left in Deauville Group Three scorer Lady Frankel.
Aidan O'Brien is double-handed with Deauville and Lancaster Bomber while the Rouget-trained Zelzal and Sea Of Grace, trained by William Haggas, complete the 10.
The supplementary stage is on Thursday.