Michael Walker has again been side-lined by back issues.
The former champion New Zealand rider, who has had a hip replacement, said initial tests indicated that was fine but he was forced to call for help when his back seized up during a race at Moonee Valley on Friday night.
Walker will undergo further tests to pinpoint the cause of the problem.
The former champion New Zealand rider, who has had a hip replacement, said initial tests indicated that was fine but he was forced to call for help when his back seized up during a race at Moonee Valley on Friday night.
Walker will undergo further tests to pinpoint the cause of the problem.