Nicky Henderson has been forced to rule Arkle Trophy hero Simonsig out for the season.
A winner at the last two Cheltenham Festivals, having landed the Neptune Novices' Hurdle in impressive style in 2012, the grey met with a setback earlier in this campaign but was expected to be back in time for the major races in the spring.
However, Henderson has now revealed that will not be the case.
"We've got to the point to make a decision to finish for the season," said Henderson.
"He's sound and will be in general exercise, the fracture line has healed up but there is a risk something will go.
"We've taken the advice we're given and hopefully he'll be ready for the King George next year."