Lalor is the new favourite for the Arkle Trophy Novices’ Chase

Kayley Woollacott-trained Lalor is the new favourite for the Arkle Trophy Novices’ Chase after previous market leader Le Richebourg was one of two high-profile defections from the Cheltenham Festival on Sunday.

Joseph O’Brien pulled Le Richebourg out after revealing that an injury had surfaced in the JP McManus-owned dual grade-one winning novice chaser following a routine piece of work at the weekend.

Le Richebourg was joined on the Festival sidelines by Nicky Henderson’s Fusil Raffles. His win in Saturday’s Adonis Hurdle at Kempton had made him the shortest price British-trained contender for the Triumph Hurdle.

Kayley Woollacott-trained Lalor is the new favourite for the Arkle Trophy Novices’ Chase

Previous market leader Le Richebourg is a high-profile defection from the Cheltenham Festival

However, a nasty cut on his near hind leg sustained in the race will rule him out of the Festival.

Bookmakers Betway make Lalor 3-1 favourite for the Arkle to gain a hugely emotional for Woollacott who has trained the gelding since her husband Richard committed suicide in January last year.

Woollacott said: ‘It is a shame for Joseph O’Brien and their team. No-one would celebrate something being out of the raced and everybody, including us, still has to get there and there is two weeks to go. But from our point of view it does open it up a bit.’

The absence of Le Richebourg also opens up the possibility that McManus-owned, Philip Hobbs-trained Defi Du Seuil could be switched to the Arkle from the longer JLT Novices’ Chase.

Betway make Defi Du Seuil 7-2 second favourite for the Arkle with Mick Channon’s Glen Forsa 4-1.

It also means Defi Du Seuil could be switched to the Arkle from the longer JLT Novices’ Chase

Meanwhile, trainer Colin Tizzard, who has Lostintranslation in the JLT and Thistlecrack and Elegant Escape joining his reigning champion Native River in the Gold Cup, has described KIlbricken Storm as the ‘forgotten horse’ of his Festival squad.

The gelding won the Albert Bartlett Novices’ Hurdle last year but has not run since struggling in a novice chase at Newbury in December. He goes for the Stayers’ Hurdle and is a 20-1 for his target, the Stayers’ Hurdle.

Tizzard, who said Kilbricken Storm had shone in a six-horse workout at Wincanton which included Native River, added: ‘He was a three-miler working against some two-mile horses but he is the one you’d take out of it. He’s in great form.’

Tizzard is likely to run dual Topham Chase winner and Grand National hope Ultragold in the Cross Country Chase against last year’s winner and subsequent Grand National winner Tiger Roll.