Victoria Derby second favourite Criterion will go into the $1.5 million blue-riband classic without another start.
But the three-year-old will have a new jockey - his fourth in a spring campaign trainer David Payne says has been timed to have him at his best for Flemington on November 2.
Craig Williams, who rode Criterion to win the Todman Stakes during the Sydney autumn carnival, has secured the Derby mount.
Criterion shortened in Derby betting to be a $7.50 chance after his last-start second to new favourite Complacent in the Spring Champion Stakes at Randwick last week when ridden by Brenton Avdulla.
"I think it is best to get a Melbourne jockey and the fact that Craig has ridden the horse and has won on him is a big plus," Payne said.
Payne said there would be no need to give Criterion a Melbourne lead-up run.
"He took a few runs to come good in the coat this preparation but he is peaking at the right time," he said.
Payne has sent Rock Hero to the spelling paddock after the colt ran unplaced in the Spring Champion.
"I think the hard run the week before (in the Dulcify Quality) told on him and he can spell now and come back a better horse in the autumn," he said.
Payne already has Craven Plate winner Honorius in Melbourne and the four-year-old will line up as one of the favourites in the David Jones Cup at Caulfield on Saturday.
Being groomed as a stud prospect, Honorius posted a maiden weight-for-age win in the Craven Plate, beating Cox Plate and Melbourne Cup contender Masked Marvel.