Aidan O’Brien has cut his assault on the Vertem Futurity to just Wembley in his bid for a record-equalling 10th victory as nine horses were declared for the Group 1 at Doncaster.

O’Brien had seven entries at the confirmation stage but has decided to rely on Wembley on Saturday as he seeks to join the late Sir Henry Cecil as the most successful trainer in one of the calendar’s highest-profile two-year-old races.

The last three winners have gone on to win the following year’s 2000 Guineas, two of them trained by O’Brien – Saxon Warrior and Magna Grecia.

Wembley has won only a Roscommon maiden from six races but has finished second in the National Stakes and the Dewhurst on his last two starts.

State Of Rest, third to Chindit in the Champagne Stakes over seven furlongs at Doncaster last month, represents O’Brien’s son Joseph – while Jim Bolger’s Mac Swiney, winner of the Futurity Stakes at the Curragh, completes the Irish raid.

Andrew Balding, who lifted the prize last year with Kameko when it was re-routed to Newcastle, saddles King Vega. The son of Lope de Vega has finished second on both his starts, the latest in the Solario Stakes at Sandown.

Roger Varian, who was successful with Kingston Hill in 2013, supplemented Baradar for £17,500 at Monday’s confirmation stage.

One Ruler, a smooth winner of the Autumn Stakes at Newmarket, will try to give Godolphin trainer Charlie Appleby a first win in this race.

Cobh, Emperor Supreme and Megallan complete the nine contenders.