Altior has been declared for Wednesday's Betway Queen Mother Champion Chase after making good progress in his bid to overcome a last-minute setback, but his participation remains in the balance.
The two-time Champion Chase winner was reported lame by Nicky Henderson on Sunday, with the trainer admitting his star chaser faces a "battle against time" to make the day-two highlight.
Speaking on Monday morning, Henderson said: "We've declared Altior on the grounds he has made good improvement from yesterday. He has sensitivity on the splint and resented you pressing it yesterday. But he's nothing like as reactive today.
"On the grounds of that improvement overnight we've got to give him every chance to run. He's on the treadmill walking and will do the same tonight. We must give him a chance."
Altior featured alongside Defi Du Seuil and Chacun Pour Soi in a seven-strong field for what has been billed of the race of the week.
Dynamite Dollars, Politologue, Sceau Royal and Bun Doran complete the line-up, with A Plus Tard and Min seemingly set for Thursday's Ryanair Chase after being taken out.