City Of Troy is among of bumper field of 16 confirmations for what looks like being the race of the season in the Juddmonte International at York on Wednesday.

Aidan O’Brien’s Derby and Eclipse winner will face his toughest test to date against some new rivals from the Classic generation and a high-class field of older horses. O’Brien has also left in Continuous, Hans Andersen and Los Angeles.

There is a strong challenge from France in Calandagan, who was so impressive at Royal Ascot for Francis-Henri Graffard, and the Jerome Reynier-trained Zarakem, runner-up in the Prince of Wales’s Stakes.

Durezza, the Japanese St Leger winner, will attempt to avenge Zenno Rob Roy’s narrow defeat in 2005.

Top filly Bluestocking is still a possible for the sponsors, while Derby runner-up Ambiente Friendly looks sure to be suited by the drop in trip for James Fanshawe.

Owen Burrows’ Alflaila has won three Group races already at York and rates a danger, as does Clive Cox’s Ghostwriter, not far behind City Of Troy in the Eclipse.

Top-quality horses such as Maljoom, Israr, Docklands and Royal Rhyme are available at big prices, indicating just how strong the contest is shaping up to be.

And further strength could be added by White Birch, who faces a key gallop on Friday which will determine whether or not he lines up.

The four-year-old has not been seen since lowering the colours of Auguste Rodin in the Tattersalls Gold Cup in May. He was a late absentee from the Prince of Wales’s Stakes at Royal Ascot due to an unsatisfactory blood test result and also missed the Eclipse having failed to fully recover.

“He’s in very good form. He’s due to have a piece of work tomorrow, Colin Keane will ride him and we’ll have a chat with the owners after that and make a decision whether he goes to York or whether he goes straight to the Irish Champion Stakes,” said George Murphy, assistant trainer to his father, John, on the Nick Luck Daily Podcast.

“Tomorrow or the next day we’ll know what way we are going.

“There are a few other races we are thinking about so it’s a final decision on what way we map out his summer and autumn campaign. He’s in super form, he had a little bit of a break and seems to have done very well so fingers crossed all goes well over the next few days.

“He had three races very close to one another, so it was probably no harm (having a break). You can’t keep going all year and there are some exciting races towards the end of the year we are very focussed on.

“The Arc is definitely still an option and it’s fairly high up on the list, but there’s the Irish Champion Stakes, the Arc and the English Champion Stakes as well so there’s plenty of options.

“We’ll know a little bit more in the coming few days. He’s in good shape and whatever will be will be.”