Tony McCoy is due to partner Black Jack Ketchum

The eight-year-old horse has been favourite to win the World Hurdle on 15 March throughout the season.

But he lost his unbeaten record to Blazing Bailey in testing conditions at the course in January, and rain has continued to hit the track.

"If the ground was like this he won't run," said O'Neill at a Cheltenham media gathering on Tuesday.

Confirming the horse's well-being, O'Neill said he would prefer to wait for Aintree or Punchestown rather than risk him in unsuitable conditions.

Soft ground is a possibiility for the start of the four-day Festival, which begins on Tuesday 13 March.

Conditions at the Gloucestershire course have tended to make the going 'good' in recent years, with drying ground leading to fast conditions.

But that appears less likely this year with heavy rainfall, and the course keen to cut down on equine accidents.

"If we were racing today the ground would be soft, - heavy in places," said clerk of the course Simon Claisse.

And he refused to rule out the possibility of testing ground, which has not been witnessed at the showpiece meeting since Desert Orchid's famous Gold Cup success in 1989.

"There are heavy bits coming down the hill on the New Course which is used on Thursday and Friday, and also on the cross-country course," said Claisse.

"We are due for a mild week this week, but there is a strong sign of some high pressure building for next week and we may well start the Festival with some nice warm, spring-like weather."

Bookmakers say it is odds-on the Festival will start with 'Good to soft' going, with 'soft' or 'good' ground the next most likely options.

Paddy Power slashed the odds on heavy going from 10-1 to 20s after Claisse's comments.