Aidan O'Brien has nominated dual Guineas hero Gleneagles for the Breeders' Cup Classic, in which he could take on American Triple Crown winner American Pharoah.

The high-class three-year-old is still in line to make an appearance in the Irish Champion Stakes on Saturday week, providing the ground is suitable.

He has missed intended outings in the Sussex Stakes and the Juddmonte International due to ground which was deemed to be too soft.

Should he not appear at Leopardstown, Gleneagles will have the Queen Elizabeth II Stakes at Ascot on Champions Day as a back-up on 17 October.

A mouthwatering duel with American Pharoah, who only finished second in the Travers Stakes at Saratoga on Saturday, could then be on the cards if Bob Baffert's colt stays in training.

However, retirement has been mooted for the son of Pioneerof The Nile since he suffered just the second defeat of his 10-race career

In a statement, O'Brien said: "Given suitable ground, Gleneagles will run in the Irish Champion Stakes on Saturday week and, failing that, he will be aimed at the Queen Elizabeth II Stakes at Ascot in October.

"His end-of-season target is the Breeders' Cup Classic at Keeneland where he may face American Pharoah."

Gleneagles has proved himself the best of his generation over a mile with Classic wins at Newmarket and the Curragh supplemented by his St James's Palace Stakes victory at Royal Ascot.

He was declared to take on the Derby winner Golden Horn over 10 furlongs at York in the Juddmonte International, but O'Brien felt the ground had too much give in it after walking the track.

The Irish Champion Stakes is also over a mile and a quarter, but if the ground goes against him again it would mean Gleneagles could have to tackle a new trip, and an alien surface in dirt, at Keeneland.