William Buick is to take some time off as he is currently awaiting results of tests after feeling unwell.
Last year’s Derby-winning jockey missed his Classic rides in France on Sunday, and he has decided to sit out this week before returning.
Buick, who is retained by Sheikh Mohammed’s powerful Godolphin operation, rides principally for trainer Charlie Appleby.
A statement on the Godolphin website said: “William Buick felt unwell this weekend, and will not be race-riding this week.
“He is undergoing tests at Addenbrookes hospital and is awaiting the test results before resuming riding.”
Buick had six rides at Ascot on Saturday, when he enjoyed a winner for Appleby aboard Expressionist.
On Thursday, he was set to ride Godolphin's No 1 Derby hope for this year, Line Of Duty, in the Al Basti Equiworld Dubai Dante Stakes.
Ispolini, in the Matchbook Yorkshire Cup on Friday, and Mythical Magic, in the Al Shaqab Lockinge Stakes at Newbury on Saturday, will be other potential high-profile rides he will miss.