Bjorn Baker's speedy colt Winning Rupert will undergo surgery to remove a bone chip later this week which will require a minimum spell of three months.
Winning Rupert finished fourth as the odds-on favourite in last Saturday's $2 million Magic Millions 3YO Guineas (1400m) at the Gold Coast.
A post-race veterinary inspection revealed the colt to be slightly short striding in the near foreleg before scans detected a bone chip in the knee on Monday.
Baker had ambitions to run Winning Rupert in the Group I TJ Smith Stakes (1200m) at Randwick during the autumn carnival but the Warwick Farm trainer is resigned to being without his talented three-year-old until the spring.
The son of Written Tycoon is likely to be kept over sprint courses in Melbourne as he looks to build on a record that currently reads five wins from six starts.