Nicky Henderson's French-bred charge burst on to the scene in Britain with a stunning display in the 2009 Feltham Novices' Chase at Kempton and has never finished outside the first three since.
Today's assignment would appear the easiest race the Cheltenham Gold Cup and double King George VI Chase winner, has had for some time but with the improving novices Unioniste and Harry Topper in the field, Waley-Cohen believes it will far a from straightforward task for the hot favourite.
He said: "It looks like quite a competitive race, as you would expect. He has come to hand a bit earlier this season, which is one reason why he is running.
"The other reason is we would quite like to go to Haydock for the Betfair Chase (November 23) having had a run under our belts. After that it would obviously be great if he could go and win a third King George."
The Paul Nicholls-trained Unioniste, second in the betting behind Long Run, won three of his five starts over fences during his debut season in Britain last term.
"Obviously, he will have to progress from what he's done up to now to get to the top level but he's a nice staying chaser and as he gets stronger I think there is improvement to come," Nicholls said.
Kim Bailey's Harry Topper looked the part when winning his first three starts over fences last season but unseated his rider at Kelso before being brought down in his last race, at the Punchestown Festival.