Kenya and Rostropovich are Aidan O'Brien's two representatives in the Homeserve Dee Stakes at Chester on Thursday.

The Ballydoyle handler has saddled four of the last six winners of this Listed Derby trial.

No horse has managed to win this prize and follow up the Investec Derby since Sir Michael Stoute's Kris Kin completed the double in 2003, although the O'Brien-trained Cliffs Of Moher came close last season, finding only stable companion Wings Of Eagles too strong in the premier classic at Epsom.

Kenya won twice as a juvenile, including the Group 3 Killavullan Stakes at Leopardstown, and steps up in distance after finishing third behind fellow O'Brien inmate Gustav Klimt in a 2,000 Guineas Trial last month.

Stablemate Rostropovich claimed a Group 2 success last term in the Futurity Stakes and travelled to France for his seasonal reappearance, placing fourth in the Prix de Fontainebleau at Longchamp.

Locally-based trainer Tom Dascombe is represented by Free Handicap runner-up Finniston Farm, while Andrew Balding saddles Feilden Stakes second Fortune's Pearl.

King's Proctor (Mark Johnston), My Lord And Master (William Haggas), Rastrelli (Charlie Appleby) and Shakour (Jason Ward) complete an eight-strong field.

O'Brien's Idaho is the likely favourite for the Boodles Diamond Ormonde Stakes later in the afternoon.

Following six consecutive appearances at Group 1 level, the five-year-old is back in Group 3 company for the first time in two years on the Roodee and is well clear on official ratings.

He faces five rivals in course and distance winner Muntahaa (John Gosden), Danehill Kodiac (Richard Hannon), Duretto (Andrew Balding), Dylan Mouth (Marco Botti) and Elidor (Mick Channon).