Nicky Henderson will give Sprinter Sacre a "full MOT" after the trainer ran out of time to get him right for the Cheltenham Festival next month.
The two-mile king was dramatically pulled up at Kempton on December 27th, where he was quickly diagnosed as suffering from an irregular heartbeat.
That problem righted itself, and he has since been closely monitored by equine specialist Celia Marr.
However, the eight-year-old did not show his usual brilliance in a piece of work on Saturday, and the decision has been taken to miss not only the Queen Mother Champion Chase, which he won last year, but also the rest of the season.
Henderson told BBC Radio 5 live: “He’s such a brilliant horse you can just tell (he wasn’t right). He was working to 90 per cent of his ability and his capacity.
“Our job is to send him back to the garage, if you like, and get him back and have a full MOT.”
Sprinter Sacre will continue to work at home during his enforced hiatus.
Henderson told At The Races: “I suppose, in a way, it’s lifted a brick off our shoulders.
“His heart is working perfectly normal, it is probably ours that hasn’t been the last few weeks.
“His heart hasn’t done anything wrong since that day at Kempton when it took 24 hours to self-right.
“He had to go to either Kempton on Friday or Newbury on Sunday as he needed a racecourse gallop and I just wouldn’t have felt comfortable taking him to a racecourse.
“Kempton was a tremendous shock to the system and there had been no clue at home there was anything wrong.
“His blood is good, his scope is clean and we can not find anything.
“I think there’s a sense of relief (that the decision has been made). It was only right to say now, it’s getting close.
“We thought it was better to say now rather than push him any further and now everybody knows where we are.
“He’ll go out second lot and have an exercise, you can’t just stop with him. We’ll keep asking questions without galloping him and at some stage he’ll go to Ceila Marr in Newmarket to be checked over and I’m sure she’ll start with his heart.”
Henderson is putting the finishing touches to his Festival line-up with Bobs Worth likely to have a racecourse gallop at Newbury on Sunday ahead of the defence of his Gold Cup crown.
The current champion put a lacklustre first run of the season at Haydock well behind him with a return to his best in the Lexus Chase at Leopardstown over Christmas.
Henderson traditionally takes some of his Festival team to Newbury this weekend for a gallop but with the ground likely to be soft, especially after racing there on Friday and Saturday, many of his stable companions will instead head to Kempton on Friday.
The Seven Barrows handler is, however, still “leaning towards Newbury” with Bobs Worth.
“Bob will appear at one of those two venues over the weekend,” said Henderson.“He doesn’t need to do a whole heap.
“I probably might be leaning towards Newbury with him so if there is a strip of ground at Newbury it might be better for him than the all-weather as he doesn’t strike me as an all-weather horse, to be honest, but we’ll see.”
