Karl Burke hopes to have Quiet Reflection back for an autumn campaign after ruling her out of Saturday's Diamond Jubilee Stakes at Royal Ascot.
A winner at Royal Ascot last year in the Commonwealth Cup, the filly took a while to come to hand this season after a succession of niggly problems.
She did make it to Haydock for the last month's Temple Stakes, where she finished 10th of 12 runners over an inadequate five furlongs on ground that was too quick, but she has now suffered another setback.
Burke said: "Unfortunately Quiet Reflection won't make it to Ascot.
"The silver lining is that it doesn't look like it would have been her ground anyway, but even if it was she wouldn't be going.
"She's just had a recurrence of the problems which affected her early in the season and it will rule her out of the July Cup, too.
"We'll hopefully have her back for an autumn campaign and the obvious races are the Sprint Cup at Haydock and Ascot on Champions Day."
Twenty-two horses were left in at the confirmation stage, headed by Henry Candy's Limato.
Aidan O'Brien has taken out Acapulco but left in Washington DC, who is due to run in the King's Stand on Tuesday.
Long On Value is set to represent American trainer Bill Mott, with Fabrice Chappet's Finsbury Square carrying French hopes along with Al Jazi (Francois Rohaut) and The Right Man (Didier Guillemin).
James Fanshawe's The Tin Man, the William Haggas-trained Tasleet and Magical Memory, from Charlie Hills' yard, are other major players.
Growl, Brando, Librisa Breeze and Suedois are still in the mix, too.