The Willie Mullins-trained eight-year-old had won each of his 14 completed starts before coming off second best to Sprinter Sacre in his two latest starts at Cheltenham and Sandown.
Bought from France, where he won his first two races, he has also won twice at Auteuil already when trained by Mullins.
Those wins came over an extended two miles and three furlongs, but he has another two furlongs to tackle this time, not to mention Simonsig, another horse trained by Nicky Henderson who has bounced back after his career appeared to be over.
“It looks a very hot race with Simonsig, Al Ferof and a few others from home,” said part-owner Colm O’Connell.
“Still, on soft ground we know ours is a serious horse.
“In a way Sandown made it clear for us. If we’d beaten Sprinter Sacre there, we’d have been building next year around going to Cheltenham (for the Queen Mother) again, but the fact we’ve met Sprinter Sacre twice on good ground and been put in our place twice, we have no excuses. He’s the better horse.
“Running over this trip is an experiment. If he stays we’ll have all sorts of options for next season and we’re hoping to pick up lots of prize-money to help us buy the next Un De Sceaux.”
Mullins also runs the veteran Thousand Stars, who is a standing dish in this race.
According to the bookmakers, Un De Sceaux may have most to fear from Simonsig, who along with Sprinter Sacre and My Tent Or Yours has been coaxed back to something approaching his best form after a very lengthy absence.
Barry Geraghty was pleased with his run at Punchestown when third to God’s Own and feels he should improve from it.
“He ran a great race the last day and you’d have to think he’d improve for it,” said Geraghty. “Nicky is just brilliant at bringing these horses back, I don’t know how he does it, but you’d have to say patience is the key.”
David Pipe’s Ballynagour won the race last year and he is back again, although on something of a retrieval mission having shown little this season. Pipe also runs Gevrey Chambertin.
Dan Skelton is sending over the evergreen 11-year-old Al Ferof, who won the Peterborough Chase and ran with great credit in the King George, Ryanair and Melling Chase.
“The ground won’t worry him but it’s a very hot race,” Skelton said.