Twelve feet.

That is what Nicky Henderson has to find if Long Run is to beat Kauto Star and keep the Betfred Cheltenham Gold Cup he won last year.

It sounds easy enough because in just over a month Long Run reduced the deficit by 54 feet from the eight lengths by which Kauto Star beat him in the Betfair Chase at Haydock in November to the one-and-a-quarter lengths – or 10 feet – that separated them when Kauto Star won that historic fifth King George VI Chase at Kempton Park on Boxing Day.

Ten days ago the path to Long Run becoming only the third horse to win successive Gold Cups in five decades appeared eased with the news Kauto Star might not run.

However, neither Henderson – nor Long Run's owner, Robert Waley-Cohen – have any desire to retain the trophy by such a default method and will be heartened by the prospect that the fifth meeting between the two giants of steeplechasing is still due to take place on Friday after Kauto Star came through a racecourse workout at Wincanton for Paul Nicholls two days ago.

"We were two-love up at the end of last season and now it's two-all so it's going to be a very interesting battle. There were a lot of people baying for Kauto Star to be retired last season. The only thing I can say is I wish Paul had listened to them," Henderson said with tongue so firmly in cheek it might have required surgical extraction. "Life would be a lot easier."

Life got just a shade more difficult on Tuesday when Henderson found himself rebutting rumours that Long Run had a problem too. Bookmakers and betting exchanges were reaching for the button marked "panic" but Henderson said: "I heard last night that he was drifting. Unless someone's been in there in the middle of the night and hit him with a hammer then I don't know why. It is most annoying because it's the last thing you need. Nothing has happened."

Henderson knew instinctively that something had to happen if Long Run was to be competitive against a resurgent opponent. The task last season for both Henderson and Sam Waley-Cohen, Long Run's amateur rider, had been to harness the horse's natural exuberance.

The thought then occurred to Henderson that the harness may now have become shackles that were inhibiting that talent. After 33 years in the job Henderson knows how to listen to his horses and had wondered whether the ear plugs that had proved such a potent weapon were now being turned against him.

When Long Run won at Newbury last month, in the Denman Chase, the earplugs were removed just before the start and Henderson is hoping the seven-year-old will heed the call to arms once more. "Maybe he's got too relaxed and needed to be a bit more aggressive. We wanted to sharpen him up a bit," Henderson explained. "It's just to take the parade out, where he'll still get plenty fizzy, and then he can have a rush of adrenaline as they jump off."

Henderson might have been tempted to use the earplugs on the jockey instead. Waley-Cohen had described the run up that final hill at Cheltenham as "like galloping into the mouth of a lion". There have been moments this season when the jockey must have felt he was putting his head in the lion's mouth with questions openly asked – wrongly – as to whether he should be riding the horse.

"I'm not going to criticise the press but we all know the thing is to build somebody up just to bring them back down again," Henderson said. "And that's what happened. He was the golden boy, amateur, Corinthian, part-timer and everybody thought that was wonderful. When things go a little bit wobbly, then it's quite fun knocking them down again. And I don't say it's unfair, but he's done nothing wrong.

"He gave him a great ride in the King George, a great ride at Newbury – say no more. These two get on really, really well together and I have total confidence in the horse and Sam riding him."

By the time the field leave the parade ring for the Gold Cup, Henderson's confidence could be sky-high if only a few of the talented squad of horses he will send to the meeting perform to expectations.

One of those will be Sprinter Sacre, the favourite for the Racing Post Arkle Trophy on Tuesday. If he wins, Henderson, who has won at the Festival 39 times since See You Then's victory in the Champion Hurdle in 1985, will draw alongside Fulke Walwyn on the all-time winners' list for trainers at the Festival.

And if Long Run can find those 12 feet, Henderson may have achieved his greatest feat of all.