William Haggas hopes to run Tasleet in the Greenlands Stakes at the Curragh on May 26 after being forced to miss Wednesday's Duke of York Stakes.
Winner of the York Group Two last season, he gave himself a knock the day before his defence and despite treatment, he was deemed not fit enough to take on star sprinter Harry Angel.
He could now be re-routed to Ireland on Saturday week.
"It was so annoying because he'd never missed a day and he would have been right to run a day later," said Haggas. "There's a Group Two at the Curragh in a couple of weeks he can go for before Ascot, if he's OK in the interim. It's very frustrating, though, as he'd been trained for the York race for months and I had him in lovely shape. He just knocked a joint so had a poultice on it overnight, but you could tell when we pulled him out Wednesday morning that he was still feeling it a bit."