Jockey Jason Benbow has suffered a fractured T6 vertebra in a trackwork fall. Benbow was taken to hospital after the fall at Caulfield on Tuesday morning.
Initial X-rays appeared clear but the Victorian Jockeys Association said further scans showed the fracture.
"Further scans have revealed that unfortunately Jason has a fractured T6 vertebra," the VJA said.
Benbow's fall came a couple of days after fellow Victorian rider, apprentice Thomas Stockdale, broke his tibia and fibula in a barrier incident at Stony Creek races.
Stockdale had surgery on the injured leg at Traralgon Base Hospital on Sunday night.
"Talking to his mother yesterday, she said that he was talking to the doctor when he can get the pins out, and he had only just got them in," VJA chief executive Matt Hyland told RSN927 on Tuesday.
"So he's a pretty keen young fella.
"It's a bit of a hiccup for him because he's been going so well, but hopefully we'll see him back in four or five months, I guess.
"It's usually somewhere between that three and five month bracket."