Willie Mullins is keeping his fingers crossed Barry Geraghty strikes up a good relationship with Un De Sceaux as the free-going gelding puts his unbeaten record on the line at Auteuil on Saturday.

The six-year-old won two French bumpers before joining the champion trainer at the start of the season and has barely come off the bridle in his five starts over hurdles, making virtually all of the running on each occasion.

With stable jockey Ruby Walsh sidelined by injury and Paul Townend set to be in action on home soil this weekend, Geraghty will come in for the plum ride as Un De Sceaux faces popular home runner Gemix in the Grade Three Prix Hypothese.

Mullins said: "I'm told he has travelled well and has schooled well over the hurdles.

"If Barry and himself get on well together on the day, hopefully he has a good chance of picking up a nice share of the prize-money.

"We won't make any plans until after he runs on Saturday."

With Mullins saddling Simenon in Saturday's Dubai Gold Cup, the trainer's son, Patrick, will be keeping a closer eye on proceedings in France.

Patrick Mullins told At The Races: "Un De Sceaux came from France and has run in France before. It's exciting.

"Barry is the man in form - he won the Champion Hurdle and the World Hurdle (at the Cheltenham Festival).

"He's obviously not a simple ride, but we think Barry will get on well with him.

"It's two miles and three (furlongs), so we're going into the unknown a bit, but Ruby thinks it won't be any problem.

"It's a Grade Three, so the penalties suit him - he is getting weight off the likes of Gemix, who won the French Champion Hurdle, beating Solwhit.

"He is probably the horse to beat, but the French Champion Hurdle is three miles two (furlongs) and this is two miles and three, which has to give us a chance.

"He just could be anything and this will tell us a lot more.

"He hasn't meet anything of the class of Gemix, but we're confident."

Geraghty is looking forward to the ride, which he picked up earlier in the week, and expects his mount to be well-suited by a return to France.

He wrote on his At The Races blog: "With Ruby unfortunately on the sidelines, Willie confirmed the ride with me on Wednesday and I'm really excited about this one.

"Ok, the French are putting some of their best hurdlers in with him but I honestly don't know how good this horse might be because he's unbeaten in all seven starts including his first two bumpers which were in the French Provinces in 2012.

"He's just got better and better with his five hurdle outings for Willie over the last 13 months and has hardly come off the bridle in any of them - and that includes the Red Mills Trial at Gowran Park in February.

"I've had a good look at his races and he gives me the impression he's going to be very much at home back in France because he's very fast and fluent over his hurdles as you need to be over there.

"Also, the ground is sure to have plenty of give in it which seems a must for him to produce his best.

"The other plus is the move up in trip to two miles and three furlongs because, although he's got gears, he's also got stamina.

"In short, he's got the lot.

"I've ridden a lot of winners for Willie in the past and I'd be more than hopeful that this will be another of them."