Early Melbourne Cup favourite Lucas Cranach is set to undergo surgery and will miss the Melbourne Spring Carnival, including Australia's greatest race in November.

The six-year-old German import has chipped a flake off a leg bone, in a recurrence of the injury which ruled him out of the Australian Cup earlier this year.

Lucas Cranach's trainer, Australian Anthony Freedman, confirmed the star import's absence, but does not expect the injury to be career threatening.

"We weren't happy with him and had another x-ray done which has revealed another small chip in his knee which needs to come out," Freedman told Radio Sport National.

"Given the time frame between now and the spring we have decided to operate and start again. The injury is in the same area as last time but it's a fresh chip."

"It's very disappointing for the owners, but we have to move on."

Freedman hopes Lucas Cranach may recover in time to contest the Group One Hong Kong Vase in December.

"There is a slight chance he may recover in time to get to Hong Kong, but everything needs to go right between now and then," he said.

"We'll have the surgery done in the next couple of days and then bring him back to the farm to let him recover."