Reigning Champion Chase winner Altior faces a fitness battle to retain his Champion Chase title on Wednesday.
Altior is looking to make it a hat-trick of Champion Chase victories having won the last two times at the festival.
Trainer Nicky Henderson announced the news earlier today just three days ahead of the Champion Chase.
After being joint favourite to get the win on Wednesday, Altior has drifted out to 3/1 following Henderson’s comments.
Henderson told The Sun: “Unfortunately Altior was lame this morning, due to an old splint that has been dormant.
“We are working away and there’s lots we can do, we have two days, but it’s an uphill battle.
“He was sound as a pound yesterday – you wouldn’t have seen a sounder horse.”
Altior had been joint favourite prior to his trainer’s comments but now the odds of both Defi du Seuil and Chacun Pour Soi have been slashed.
Henderson had tweeted just over 48 hours ago, saying his horse was looking ‘relaxed’ ahead of the race on Wednesday.
It is believed that Altior is suffering from an ‘old splint’ when he was pulled out of his box.
The Champion Chase is on Wednesday 11th March at 15:30.