Fundamentalist, a leading fancy for the Irish Independent Arkle Challenge Trophy Chase, has been ruled out for the season with a tendon injury.
The seven-year-old, who was a low as 6-1 with some bookmakers for the Cheltenham Festival event, disappointed on his last start when he unseated jockey Carl Llewellyn in the "Dipper" Novices' Chase at Prestbury Park.
Fundamentalist had previously notched up two impressive wins over fences and trainer Nigel Twiston-Davies had thought his poor run was due to sore shins.
However, a more serious tendon problem has been discovered and Fundamentalist is set to be off the track until next year.
"It's very likely connected to his last run," Twiston-Davies told the Independent. "It may be that there was a little bit of damage in there that was undetectable to hand or eye.
"After his run last time we swam him for 10 days and he had just started back cantering when this flared up. He's got a warm leg, a tendon. We have scanned him and there's a tiny bit of damage. It's a very mild one, but, as they say, you can't be just a little bit pregnant.
"The prognosis is that he will not run again until this time next year. We will keep him here and treat him as necessary."
Fundamentalist won the Royal & SunAlliance Novices' Hurdle at the Festival last year and he was also a favourite for this year's Royal & SunAlliance Novices' Chase.