Coneygree will miss the King George VI Chase at Kempton on Boxing Day.
The 2015 Cheltenham Gold Cup winner, who returned from a year off the track last month to finish second to Cue Card in the Betfair Chase at Haydock, is said to be “fragile” and “not himself”.
The Mark Bradstock-trained gelding underperformed in a gallop on Saturday.
Bradstock’s wife and assistant Sara said: “I know every breath he takes, every step he takes, I know exactly how he is and he’s just not feeling good.”
Bradstock said on Twitter that next year’s Gold Cup remains the priority for Coneygree.