Leading Cheltenham Gold Cup contender Cue Card has been ruled out of the showpiece meeting by trainer Colin Tizzard.
A dual Festival winner having claimed the Champion Bumper in 2010 and the Ryanair Chase last year, the eight-year-old appeared bound for a tilt at the Cheltenham Gold Cup.
The Cheltenham bid came around following success in the Betfair Chase at Haydock and a fine second in the King George VI Chase at Kempton on Boxing Day.
However, with little over two weeks to go, Cue Card has pulled muscles and English trainer Tizzard has had no option but to take him out of the Betfred-sponsored Gold Cup and Ryanair Chase reckoning.
Tizzard said: "Unfortunately he has pulled muscles behind and he won't be running at the Cheltenham Festival.
"We first noticed it last week. It was only a small thing then and it is only small now, but we cantered him this morning and he is still not right.
"He hasn't got any better and you can't be going to Cheltenham 90 per cent.
"The horse has looked after me for the last four years and it is my turn to look after him now.
"He's been so good to me and he's not going to be ready for the Festival."
Asked whether his stable star could be back in action at the Grand National meeting at Aintree in April, Tizzard said: "Hopefully, but we need to get him right first."
Favourite for the Gold Cup is reigning champion Bobs Worth, whose trainer Nicky Henderson extended his sympathy to Tizzard and his team.
Henderson, who himself has had to rule stable star Sprinter Sacre out of Cheltenham in recent days, said: "That's awful for them and it just goes to show it's a bloody difficult game. I'm very sorry for them."