Westover will face a maximum of five rivals in the King George VI And Queen Elizabeth Qipco Stakes at Ascot on Saturday.
A luckless third in the Derby at Epsom, Ralph Beckett's star colt gained compensation when routing his rivals in the Irish Derby at the Curragh earlier this month.
A rematch with his Epsom conqueror Desert Crown looked to be on the cards in this weekend's midsummer showpiece, but as expected the latter has been taken out following a well-publicised setback.
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In his absence, Westover will be a hot favourite to add the King George to his big-race CV in the hands of Irish champion jockey Colin Keane. John and Thady Gosden have confirmed both Emily Upjohn and last year's runner-up Mishriff.
Emily Upjohn has been rerouted after missing Saturday's Irish Oaks due to travel complications, while connections of Mishriff will be hopeful he can go one better than when chasing home Adayar 12 months ago after finishing a close second to French raider Vadeni in the Eclipse.
Last season's shock Arc winner Torquator Tasso has been confirmed an intended runner for German trainer Marcel Weiss, while Pyledriver is set to represent William Muir and Chris Grassick after finding the now sidelined Hukum too strong when defending his crown in the Coronation Cup at Epsom.
Joint-trainer Muir is looking forward to running their six-time winner in a race he believes is one of the highlights of the summer and also confirmed PJ McDonald will take over in the saddle aboard the course-and-distance scorer as regular rider Martin Dwyer is sidelined by injury.
"PJ McDonald is going to ride him and he's going to be the man until Martin (Dwyer) recovers.
"I said to him if you can commit, I'll commit to you. Listen, there's some fantastic jockeys and let's be quite fair, there were some fantastic jockeys and their agents ringing up for the ride on him, which you would expect.
"There is no slight against any one of them because they are all top class, but I wanted someone I could be consistent with. The other boys all have their jobs and if we get to the Arc, they are going definitely to have their runners. PJ has ridden him once and won on him once and we're going to stick with him."
The small but select field is completed by Broome, who is Aidan O'Brien's sole representative and was last seen winning the Hardwicke Stakes over the course and distance at the Royal meeting.