Champion trainer Paul Nicholls has reported that his two King George VI Chase contenders have both returned under a cloud after running below expectations, writes Elliot Slater.

The great Kauto Star was bidding for a historic fifth successive victory in the Grade 1 showpiece contest, but after coming under pressure four from home and blundering away any faint chance he might have had when a four-length second at the penultimate fence, he eventually came home third behind the Nicky Henderson-trained pair of Long Run and Riverside Theatre.

Those that observed the 11-year-old after the contest observed that he looked particularly tired, significantly more so than in previous races. On Sunday morning Nicholls commented on his blog that Clive Smith's gelding had suffered a “small bleed” after the race but that as of the following morning he was OK and the plan is still to go of the Cheltenham Gold Cup 2011 on March 18.

This first ever report from the Nicholls camp of a burst vessel from the great horse prompted a couple of firms to ease Kauto Star's odds out to as big as 12/1 for the championship event, although as Cheltenham 2011 tips go he doesn't look the best.

The Nightingale, stable companion of Kauto Star, was seen by many judges as potentially the biggest obstacle to a five-timer in the race for the former champion, but he was under pressure a long way from home and Sam Thomas eventually pulled him up before the third last. Nicholls reported that the horse had suffered from a “fibrillating heart”, the same ailment that caused the mighty Denman to miss a significant time out of training, and the prospects are likely to be the same for the eight-year-old who was such an impressive winner at Down Royal in November.

The Nightingale has been removed from the ante-post list for the Ryanair Chase, the race that was his intended target at the Cheltenham Festival.