Former apprentice Stephen Brown Jr remains in a induced coma following a fall in a Wangaratta jump-out.
The Victorian Jockeys' Association released a statement on Thursday saying Brown remains in the intensive care unit of the Royal Melbourne Hospital.
"Doctors are continuing to closely monitor his head injuries," the VJA said.
"(The) family appreciates all the well wishes."
Brown was injured in the fall at Wangaratta in north-east Victoria on Wednesday and placed in an induced coma by medical officers before being flown to the Melbourne hospital.
Earlier VJA chief executive Matthew Hyland said there were some positive signs late on Wednesday night.
"When I left last night the latest update was the doctors were a little more positive with the scans and the tests they ran," Hyland told RSN927.
Hyland said the details he had around the fall were sketchy but he believed the horse Brown was riding broke down resulting in another falling over the top.
"He's got cracked ribs, a crack in his neck and a punctured lung as well, but the main concern is with his brain," Hyland said.
Brown was indentured to his father Stephen and constantly faced weight battles throughout his career.
His last race ride was at The Valley last November before he retired, becoming a registered track rider.