Johnny Murtagh is to see a specialist on Wednesday after scans revealed the leading rider fractured a cheekbone in a fall at the Curragh on Sunday.
Murtagh was injured in an incident leaving the parade ring on Lottie Dod prior to the Group One Keeneland Phoenix Stakes and gave up his remaining rides.
The jockey was in St James's Hospital in Dublin on Monday where his injury was confirmed.
The Irish Turf Club's Dr Adrian McGoldrick said: "I've just spoken to Johnny and he has confirmed he has a hairline fracture of his zygoma. That was what I thought on Sunday and it has been confirmed this morning.
"He will return to see his specialist on Wednesday and then they will decide what needs to be done.
"He will obviously be stood down until Wednesday and we will hopefully have more news after Johnny has seen his specialist again."
Another rider in the wars on an eventful afternoon was Joseph O'Brien, who was thrown to the ground when Cristoforo Colombo came down in the Phoenix Stakes.
He, however, escaped with only soft tissue damage and was back riding out on Monday morning.