Leading Epsom Oaks contender So Mi Dar has been ruled out of the Classic with mild lameness.
Trainer John Gosden said the problem was not serious but was enough to put her out of the Oaks on June 3.
She had been as short as 5-2 to challenge the Aidan O’Brien-trained 1000 Guineas winner Minding, the odds-on favourite.
“We would call it a one to two out of five to grade it,” Gosden said.
“She may well come right in ten days, but you cannot go to any major race thinking you can walk for ten days and suddenly be ready.
“I’m sure she’ll probably be back for the Irish Oaks.”
The Irish Classic is at The Curragh on July 16.