Dual Champion Hurdle winner Buveur D'Air looks set to miss the rest of the season due to the freak injury he suffered at Newcastle, according to trainer Nicky Henderson.
He underwent surgery on Sunday after returning with a splinter of wood in his foot following his defeat at 2-13 in the Fighting Fifth Hurdle on Saturday.
Henderson said on Sunday: "It is very serious and I hope it's not career-threatening but we won't know for a week or two. However, it seems certain we may have to give the rest of this season a miss.
"It's like having a large splinter under your nail and the only way you are going to get it out is to go in and operate on it. The only good thing about all of this is that the injury has not touched the horse's coffin bone, which is just above the hoof."
Henderson described the injury as a "freak" occurrence on Racing TV later on Sunday and said: "It's not possible to even think how you could do it.
"It has gone in through the top of the coronet band and right underneath the hoof. It's very sore.
"It's a matter of getting this piece of wood out from under his hoof. Then it's a matter of how long it takes for the hoof to grow back over, which will undoubtedly be some considerable time."
Buveur D'Air was operated on by vet David Mathieson and his team at Donnington Grove in Newbury on Sunday morning.
Henderson said in his Unibet blog: "The procedure went well and they were able to do it without having to put him under a general anaesthetic which can sometimes cause problems when the horse comes round and they can often fall when attempting to get back up. But thankfully the removal was conducted with him standing up.
"Buveur D'Air's welfare and health is of paramount importance and I simply cannot speculate as to how long it will take to get him back and if/when his next race will be. This in an injury which will not be resolved overnight so we will assess the situation on a day-to-day basis but he is in extremely safe hands and will get the best treatment he can."
Barry Geraghty dismounted Buveur D'Air after the line, following his defeat by Cornerstone Lad on Saturday and explained his mount, who hit the second-last flight, had a splinter of wood in the lower section of his off-fore.
Geraghty has partnered the eight-year-old on 12 of his last 14 starts, and said he knew something was not right with his old ally shortly after the line.
The jockey said on Sunday: "I thought coming down to the last that he would win, and it would be just a case of hands and heels but he just didn't pick up the way he usually does. He just struggled a bit in the last 100 yards.
"I knew straight away when we pulled up afterwards that something wasn't right. That said, we should take nothing away from the winner.
"I'd say it was very sore and he was really feeling it. Could you imagine if something like that happened to one of us? It wouldn't be very nice, that's for sure."
Some bookmakers kept Buveur D'Air in the betting for the Champion Hurdle, on March 10, for which Saldier and Klassical Dream were contesting favouritism at a best-priced 5-1 on Sunday.
Plans for Cornerstone Lad have yet to be finalised and trainer Micky Hammond said on Sunday: "He's fine after the race but he wouldn't be running again this side of Christmas."
Buveur D'Air suffered his potentially season-ending injury jumping a wooden hurdle, part of which became lodged in his foot, a moment that has focused attention on the safety of the traditional obstacle.
A total of 13 British tracks now use padded hurdles, which were first trialled in 2013 with the aim of reducing the faller rate and the risk of injury.
A BHA spokesman said: "Padded hurdles have shown reduced injury rates. However, they haven’t removed injuries entirely.
"It is still possible that a horse can pick up a splinter going over a padded hurdle, although admittedly it is less likely. The rollout has been phased in order to ensure there are no unintended consequences."
Padded hurdles could be superceded in time as a project overseen by the Horse Welfare Board, in conjunction with the RSPCA and University of Southampton, is working on a new design of collapsible hurdle, which is also drawing on how horses perceive colours.
It is expected that courses will want to see how that develops before investing in padded hurdles.