Johnny Murtagh could be set for a spell on the sidelines after an incident leaving the parade ring on Lottie Dod in the Keeneland Phoenix Stakes at the Curragh.
Murtagh was taken for X-rays on a facial injury and is set for further tests on Monday.
The Turf Club's Dr Adrian McGoldrick said: "Johnny has fractured a small bone under his eye and he will have further tests done on a larger cheekbone tomorrow morning which I am a bit concerned about."
Another rider in the wars was Joseph O'Brien, who was thrown to the ground when Cristoforo Colombo came down in the race itself, when short of room a furlong out.
McGoldrick said: "Joseph has a soft tissue injury on his leg. I think he was quite fortunate but he will also have the injury further assessed tomorrow."