Aidan O'Brien relies solely on the supplemented Kingsbarns in Saturday's Racing Post Trophy at Doncaster, the final Group One of the British Flat season.

A total of 15 entries earlier in the week has been whittled down to a field of just seven runners, but it is remains a competitive contest.

O'Brien has taken out Battle Of Marengo, ante-post favourite earlier in the week, suggesting his seven-length Navan maiden winner Kingsbarns has been showing him all the right signs at home.

Jim Bolger never shirks a challenge, though, and takes him on with his gritty Autumn Stakes winner Trading Leather, who was beaten by Battle Of Marengo in a Listed race on his debut.

There is a third strong Irish challenger in the shape of Andy Oliver's First Cornerstone, an impressive winner of the Futurity Stakes in heavy ground.

A second supplementary entry was made on Monday and that was Richard Hannon's Van Der Neer, unbeaten after wins at Yarmouth and Leicester. Hannon has decided against running Havana Gold.

Mark Johnston's Steeler is another big contender having won the Royal Lodge in game style for Kieren Fallon.

David Simcock's Birdman and Harry Dunlop's Sir Patrick Moore complete the line-up.