Aidan O'Brien now believes the triple champion hurdler Istabraq was lazy instead of tired during his New Year's Eve comeback race which resulted in that dramatic last-flight fall at Leopardstown.

The Ballydoyle trainer also hasn't ruled out giving Istabraq a racecourse school as part of his Cheltenham preparations but admits Sunday week's AIG Europe Champion Hurdle is a more likely option.

O'Brien yesterday reported Istabraq as being in good form but denied any suggestion the great horse's workload has been increased, saying: "He was plenty fit at Leopardstown."

He expanded: "Istabraq lost very little weight from that run. In fact, he lost a lot less than our two other horses who ran that day, Kilcash Castle and Darapour.

"I thought he had looked very tired going to the hurdle but obviously he was just lazing. That's very like him at this time of the year. He can run lazily in the early part of the season."

O'Brien added: "It's a strong possibility that Istabraq will run in the AIG but it's not certain. We're keeping him ticking over at the moment but if he wasn't to run in that he could be given a good racecourse school."

O'Brien also has Theatreworld among the 11 AIG entries, but he is considered a more doubtful runner.

Istabraq's former conqueror, Limestone Lad, has had the Stayers' Hurdle confirmed as his Cheltenham Festival target and will next appear at Naas in 16 days' time before a final preparation pit-stop in Navan's Boyne Hurdle next month.

Paddy Power has had more support for Sunday's Pierse Handicap Hurdle favourite Grinkov, and Charlie Swan's mount is now a 6 to 1 favourite.

Another significant ante-post mover is the Dermot Weldtrained Moving On Up, a possible mount for the British champion jockey Tony McCoy, who is now 12 to 1 after one punter bet £1,000 to win £14,000.

Another notable weekend runner could be the star chaser Dorans Pride, who may carry topweight in Saturday's Proudstown Handicap Hurdle at Navan.