Hennessy Gold Cup favourite Bobs Worth's participation in Saturday's big race will not be confirmed until trainer Nicky Henderson has walked the course at Newbury and spoken with connections.
The trainer was inspecting the Berkshire track on Tuesday afternoon as he is worried about potentially heavy ground and wanted time to mull over his thoughts.
A dual Cheltenham Festival winner, Bobs Worth has not been seen since beating First Lieutenant in the RSA Chase last March.
"We're nervous about it (the ground) and I can't just make a decision," he said.
"I'd have to say there's an element of doubt and I'll walk the course in the afternoon and then talk to the owners.
"The gallops here are as soft as I've ever seen, but he has been very happy up the grass and worked today.
"Newbury was the obvious place to go, so we'll have to see. After that, there's only the intermediate chase at Sandown next week, but I don't want to run him right-handed.
"He won't go for the King George, but I will make an entry for the Lexus over Christmas, as they do sometimes get decent ground at Leopardstown."
Henderson's other Hennessy entry, the Irish recruit and recent Ascot winner Roberto Goldback, will not be running.
"The handicapper decided to put him up 13lb for Ascot, when all that happened was that it was his first run on decent ground," he said. "I'm inclined to run him in the two-and-a-half-mile race at Newbury on the Friday (Sportingbet Open Handicap Chase).
Sky Bet have pushed Bobs Worth out to 4/1 for the Hennessy Gold Cup and Head of Racing Richard Horner said:
"With the ground likely to be riding very testing and Bobs Worth unproven on that type of surface punters are looking elsewhere for a big price alternative to the long-time market leader.
"We have pushed his price out to 4/1 from 10/3 after good support for the likes of proven mudlarks such as Tidal Bay and Alfie Spinner."