Jockey Ana O'Brien is expected to be sidelined for three to four months recovering from back injuries suffered in a fall.

O'Brien, the 21-year-old daughter of champion trainer Aidan O'Brien, came off in a race at Killarney on Tuesday.

Her trainer brother Joseph issued a statement saying she was not likely to require surgery.

"Ana is feeling much better today, thank God," O'Brien said.

"She had an MRI that confirmed three vertebral fractures at C1, T5 and T6. Her facial fractures will be assessed in the coming days.

"Thankfully we don't think she's going to need any surgery and is going to be treated with a neck and back brace instead. She would like to thank everybody for all their kind thoughts and prayers."