Last season's World Hurdle runner-up is a favourite ahead of the Grade One race, but is at the centre of an injury scare after one of his shoes came off.

"We have a problem with Punchestowns on his near-fore," said Henderson.

"We found him to be lame on his foot again last night (Thursday). We will monitor it and just see how it goes."

The scare has sparked rumours about Punchestowns' participation in the race at all, prompting Henderson's other RSA Chase candidate Long Run to take over from his stable companion at the head of the betting with many bookmakers.

And Henderson conceded: "A similar thing happened last weekend and we had to take his shoe off, but it cleared up quickly and he spent a couple of days swimming, so didn't really miss anything.

"He worked on Wednesday and I couldn't have been more thrilled.

"The plan was to school him today, which we couldn't do anyway due to the frost, as it was still minus 7C at 7am with us. We were then going to bring him to work here at Newbury on Sunday, but we found him to be lame on his foot again last night.

"We have X-rayed it and there is nothing there. I can't say any more than that at the moment.

"The last time it happened he was sound within 24 to 48 hours and he loved going swimming, but I did want to get another run into him and that hasn't happened and now there is this, so I am just warning people."