Kicking King was in brilliant form to win the KIng George VI Chase at Sandown on Boxing Day

"On veterinary advice, myself and his owner Conor Clarkson have decided the horse will not run in the Gold Cup," said the horse's trainer, Tom Taaffe.

The eight-year gelding had been the 7-4 favourite with both William Hill and Ladbrokes to win at Cheltenham.

Kicking King returned to form on Boxing Day when he won the Stan James King George VI Chase at Sandown.

But it was during that race that Taaffe thinks the injury occurred.

The strain is in the upper third of his tendon, which is good news Tom Taaffe Kicking King's trainer

"Nothing showed up for two days, but we were watching him and thought he had just banged his leg until we got it assessed," he said.

"He has been scanned intensively by my vet Jimmy Kelly in Naas and the strain is in the upper third of his tendon, which is good news.

"If it was at the bottom it can be difficult to get them back, but they can often recover well from upper strains.

"I would hope to give him walking exercise, but he will definitely not be back this season.

I'd like to think we would have him back on the track next Christmas Tom Taaffe

"His target is now the 2007 Gold Cup. He has had good healing powers in the past and I would hope he has a similar response to this.

"I'd like to think we would have him back on the track next Christmas with a view of then going to Cheltenham."

Kicking King had been the 7-4 favourite with both William Hill and Ladbrokes to take his second Gold Cup.

Beef Or Salmon is the new 5-1 favourite with Coral for the race, having been cut from 10-1.

Kicking King's injury comes two months after three-time Gold Cup winner Best Mate collapsed and died of a suspected heart attack during a race at Exeter.

Another leading Gold Cup candidate, Trabolgan, was ruled out of the big race in December.