Top jockey Damian Browne will seek further medical advice early next week to see if he needs surgery to correct a jaw injury.
Browne stood down from riding at Doomben on Saturday after an incident at trackwork earlier in the day.
Chief steward Dan Auricsh said Browne suffered a jaw injury when he was struck in the face by a horse's head.
"He was in considerable pain with a swollen jaw and was not capable of riding,' Auricsh said.
Browne's manager Glen Courtney said Browne feared he might need surgery and would seek further advice.
Browne was Queensland's leading rider during the winter and won the Group One Kingsford Smith Cup on Impending.
He is currently awaiting an internal review of a stewards' decision to suspend him for two months on a handling charge from a race at Caloundra last month.