The opening day of York’s Ebor meeting stages one of the UK’s most prestigious middle distance flat races, the Juddmonte International Stakes – previously won by the likes of Frankel and Sea the Stars.

Dual Derby winner Australia isn’t quite in that bracket yet, but might not be too far behind with an authoritative win in the Group One contest, which forms part of the British Champion Series.

Trainer Aidan O'Brien has issued concerns over the potential fitness of his Epsom and Curragh Classic winner ahead of being pitched into all-aged competition for the first time.

O'Brien said: "He has done very well and is just ready to start back again. I suppose, because he has done so well, we are a little bit worried about his fitness. But really, when you give a horse a break - especially a three-year-old - going into the autumn, you want him to do well. He did well, he did very well."

With just five rivals lining up, the trainer's son Joseph is set to slim down to 8st 12lb to keep the partnership intact.

Just two older horses are turning up, with the Sir Michael Stoute-trained Telescope and William Haggas' stable star Mukhadram both proven top-notchers, having finished second and third respectively in the King George at Ascot last month.

Harry Herbert, representing Telescope's owners Highclere Thoroughbred Racing, said: “Potentially I think we all think there could be more to come from the horse, but that was still a wonderful performance. Now that he is fully fit and on the right ground we are seeing the real Telescope.”

Mukhadram had previously claimed a first Group One in Sandown's Coral-Eclipse, while Telescope impressed in the Hardwicke Stakes at the Royal meeting.

Kevin Ryan's French Derby winner, The Grey Gatsby, is an interesting contender, returning to the scene of his victory in the Dante Stakes earlier in the year. Peter Chapple-Hyam's Arod has ground to make up on Australia on Epsom form, but is expected to be more effective over a mile and a quarter. Australia's stable companion Kingfisher completes the field.