Wednesday, 22 Feb 2017 : The nine-year-old won his first four starts over fences, including a three-length victory over Cue Card in the King George VI Chase on Boxing Day.
“The vet scanned him this morning and it’s a slight tendon tear,” said trainer Colin Tizzard.
“We’ve seen it at every yard and it happens every year.”
Native River, the Hennessy Gold Cup and Welsh Grand National winner and Thistlecrack’s stable-mate at Tizzard’s yard, is now favourite for the Festival showpiece on 17 March.
Cue Card, another Tizzard-trained prospect, and 2015 Gold Cup runner-up Djakadam are also challengers.
Thistlecrack has won eight times in 11 starts over hurdles, but came second to Many Clouds in the Cotswold Chase at Cheltenham at the end of January.
Jockey Tom Scudamore has guided Thistlecrack since April 2015
Many Clouds subsequently collapsed and died after the winning post.
Source By: Internet