With soft ground seemingly certain at Kempton, connections of the Willie Mullins-trained gelding are favouring the Lexus for the dual Cheltenham Festival winner, meaning another clash with Peter Casey's Flemenstar, this time over three miles.
"Because of the weather we are leaning towards Leopardstown," said Eddie O'Leary, racing manager to owners Gigginstown House Stud.
"I think there is as much rain at Kempton as there is over here, so there is going to be no better ground over there."
Sir Des Champs clashed with Flemenstar earlier this month in the John Durkan Chase at Punchestown over two and a half miles, with the Casey runner coming out on top by five lengths.
David Bridgwater could turn to Tony McCoy for his King George hope The Giant Bolster.
He was ridden on Merseyside by Tom Scudamore, who has been on board for eight of the gelding's last nine starts.
However, Scudamore would be required to ride Grands Crus for David Pipe should he take his chance.
Bridgwater said: "He's Tom's ride, but if Grands Crus runs he has to ride that, end of story.
In other jockey news, Barry Geraghty has yet to make a decision whether he will ride Finian's Rainbow or Riverside Theatre.
Finian's Rainbow won the Queen Mother Champion Chase at last season's Cheltenham Festival, but struggled in heavy ground on his reappearance at Ascot in November.
Riverside Theatre, who finished second to Long Run in the King George two seasons ago, landed the Ryanair Chase at the Festival in March but has not been seen since he was pulled up at Aintree in April.
Geraghty told At The Races: "It's a very difficult call - you don't want to be offending anyone, either.
"Both were good winners at the Festival and I think both would get the trip.
"It's a very difficult one and we'll let it run to the wire."
Confirming some of his festive running plans, Paul Nicholls said: "Kauto Stone will run (in the King George), he's in good shape and he won't mind the ground.
"Poungach will run in the Feltham and Dodging Bullets will go to Kempton, too (Christmas Hurdle).
"Tidal Bay goes for the Lexus later in the week."