Sandown's loss could be Ascot's gain after Nicky Henderson was forced to rule Sprinter Sacre out of the BetVictor Tingle Creek Chase at Sandown on Saturday.
The star of the National Hunt scene returned a dirty tracheal wash earlier in the week and his results are still not 100% leaving the champion trainer to take the agonising decision not to declare his stable star for his intended seasonal reappearance.
Instead, while Henderson mentioned the possibility of the Desert Orchid Chase at Kempton over Christmas, the Clarence House Chase, formerly known as the Victor Chandler, at Ascot on January 18 is now his most likely port of call.
"We've taken the decision not to run. We've re-tested him and just got the results back," said the Seven Barrows handler.
"Having spoken to all the vets possible and his owner Caroline Mould, we've decided not to go.
"His figures have improved quite dramatically since Monday but there was just one figure that was causing us concern.
"I had a figure in my mind that I wanted to see today and it just wasn't quite there.
"We can't take any chances with him and having told everyone earlier in the week that he had a problem and if we ran him and god forbid something happened, then everyone would ask what we are doing running him.
"I suppose there's the Desert Orchid Chase at Kempton but we'll probably wait for the Victor Chandler Chase now.
"Now we can get him on some medication and it is the sort of thing that will clear up in no time but obviously we couldn't give him anything earlier in the week.
"Nico De Boinville rides him everyday and having ridden him this morning he said he still looks and feels fantastic and that he was in tip-top form and that you could never tell externally that there was a little something a miss.
"However, sadly we'll have to bypass the weekend. It's marginal and we'd always wanted to start here but we'll have to make a new plan.
"It's very disappointing for everybody but Captain Conan will take his place and he's a horse on the upgrade."
Nine horses were declared, including Captain Conan, who took the Henry VIII Novices' Chase on this card 12 months ago for his third Grade One course success.
Apart from Sprinter Sacre, the only other withdrawal was Hinterland. leaving his trainer Paul Nicholls to be represented by Kauto Stone, who was runner-up to Sizing Europe in this race in 2011.
Sire de Grugy showed his liking for the track when winning the Celebration Chase in April and his trainer Gary More is hoping a return to Esher will spark the seven-year-old into an improved performance following his defeat by Kid Cassidy in the Shloer Chase at Cheltenham.
The Mick Channon-trained Somersby will attempt to supplement his victory in the Haldon Gold Cup at Exeter.
Completing the line-up are His Excellency, Mad Moose, Oiseau de Nuit, Tataniano and Viva Colonia.
Sprinter Sacre would have been a long odds-on chance for the Grade One showpiece and in his absence Sire de Grugy has been installed the 7-4 favourite.
BetVictor spokesman Charlie McCann said: "Whilst the absence of the champion chaser is a blow to all the race looks wide open without Sprinter Sacre and we make Gary Moore's Sire Du Grugy 7-4 favourite from Captain Conan at 5-2 and Somersby 11-4."