George Washington was found to be lame after his defeat in the Boylesports Irish 2000 Guineas and plans to run the colt at Royal Ascot are now on hold.
Initially, the son of Danehill was thought to have come out of his two length reverse behind Araafa fine but when the horse was trotted out yesterday morning he was found to be slightly lame.
Trainer Aidan O'Brien has discovered that the brilliant Newmarket Guineas winner has pulled muscles over a hip and his appearance in the St James's Palace Stakes, where he was set for a rematch with Araafa, is now in jeopardy.
"George Washington seemed to be fine when we walked him on Sunday," O'Brien told the Racing Post. "But when we trotted him this morning we discovered that something wasn't right.
"He has pulled some muscles above his hip and it will be a few days before we know how long it will be before he can run again. Plans for him are on hold."