Idaho© Photo Healy Racing
There is a dual Irish challenge on the Hardwicke Stakes at Royal Ascot on Saturday.
The Aidan O'Brien-trained Idaho and Jim Bolger's Stellar Mass make the trip for the Group Two over a mile and a half, but Frontiersman has been ruled out of due to an unsatisfactory scope.
The four-year-old, trained by Charlie Appleby, was last seen finishing second to O'Brien's Prince of Wales's hero Highland Reel in the Coronation Cup.
Godolphin tweeted: "Frontiersman will not be declared for the Hardwicke Stakes at Royal Ascot due to a bad scope this morning."
Fourteen horses have been declared for the 12-furlong prize, including last year's winner Dartmouth.
The five-year-old, trained by Sir Michael Stoute and owned by the Queen, returned to action with victory in the Yorkshire Cup last month.
Stablemate Across The Stars also takes his chance.
Last year's Prince of Wales's Stakes winner My Dream Boat represents Clive Cox, while John Gosden has a strong hand with Muntahaa, Western Hymn and Wings Of Desire, who finished fourth in the Derby and second in the King George last term.
However, Gosden has stated both Western Hymn and Wings Of Desire will only run if the ground is deemed suitable.
The field is completed by Arthenus, Barsanti, Chemical Charge, Dal Harraild, Prize Money and Second Step.
