Trainer Robert Cowell says the step up to six furlongs for Jwala is a worry ahead of her run in the Hong Kong Sprint at Sha Tin on December 8.

Last season's Nunthorpe Stakes winner strives to become the first European horse to take the Group One sprint since its inception in 1999.

Jwala showed her 40-1 triumph at York in August to be no fluke after she finished a close-up fourth in the Prix de l'Abbaye on Arc weekend at Longchamp in October.

Cowell is, however, wary about the four-year-old filly's ability to go the distance in the Far East.

"The step up to six furlongs is an obvious concern and we aren't particularly confident that she will get it, but she has a relaxed style of racing and will give herself every chance," he said.

"Jwala's preparation for Hong Kong has gone well. She's in good form and ready to go.

"She was half a length in front at the furlong pole (in the Prix de l'Abbaye), but the ground just caught her out.

"The first, second and third were all soft-ground specialists and she's not so we were delighted.

"Going round a bend won't be a problem."