Sir Des Champs will line up in the Betfred Cheltenham Gold Cup today with a new jockey after regualr pilot Davy Russell was ruled out with a punctured lung.

Russell suffered a fall on Wednesday from Un Beau Matin in the Coral Cup but attempted to ride in the first two races yesterday.

After finishing unplaced on Argocat in the Jewson and Stonemaster in the Pertemps Final, Russell was struggling to breath before his problem was diagnosed. Nevertheless, despite his pilot still not being decided, trainer Willie Mullins has been happy with his charge's preperations.

"He's going well and improving all season," said Mullins of the two-time Festival winner. "He likes the course, he'll like the ground and on form, he's up there with the best of them. Let's hope he's good enough.

"He's two out of two [at Cheltenham]. Bobs Worth is four out of four and he's got pretty good form going in there. If he can run his usual good race, it's all to play for."

With no Kauto Star to call on for the first time in six years Paul Nicholls is relying on Silviniaco Conti in the Betfred Cheltenham Gold Cup. He looks to have had the ideal build-up, winning the Charlie Hall at Wetherby, the Betfair Chase at Haydock and the Denman Chase at Newbury.

Nicholls decided not to send him to Cheltenham as a novice last year and while some are viewing that as a negative, not so the champion trainer. "He's won his last four chases, and he's three from three this year. He's run in great Gold Cup trials and he keeps winning," said the handler. "He does everything right – he travels well and he keeps winning. He's not flashy, he just does the job – that's what I like about him."

Only Nicky Henderson's Long Run represents a link back to the "golden era" of chasers that also included Denman and Imperial Commander. He could only finish third last year but won a second King George in December to add to his Gold Cup of two years ago.

"I think we're happy, he came back and won the King George," said the trainer. "He likes Cheltenham and I do think he was a bit flat last year – I can't say he is miles better this year, but I think he is better. Long Run has got his King George back, he's got to get his Gold Cup back and probably shouldn't be twice the price of Bobs Worth."

Bobs Worth is his Henderson-trained stablemate and is defending an unbeaten Cheltenham record.

Henderson said: "He missed a prep race, but the ground was so bad at the time – we've had soft ground since October. He's a good horse. He's proved he's a Grade 1 winner as a novice, but not in this league.But then again, it's a very open year."

The JCB Triumph Hurdle is never anything but brutally competitive but the nature of this truncated season means not as much has been seen of the principals than might ordinarily be the case.

Henderson can make it a trio of wins in the last five years through Rolling Star, who very much fits the mould of Soldatino and Zaynar as a lightly raced French recruit.

Both of those had barely been seen on these shores, and Rolling Star has appeared only once, but he made a big impression when quickening away from Irish Saint in what looked a match-race at this course in late January.

Irish Saint boosted the form by taking the Adonis at Kempton, and Rolling Star is not totally inexperienced as he ran plenty of times on the Flat and also scored over French hurdles at Auteuil in November. He looks the sensible option.

Henderson can strike again later with Utopie Des Bordes taking advantage of her 7lb mares' allowance in the Albert Bartlett Novices' Hurdle.