Trainer James Cummings says star colt Broadsiding faces his "ultimate test" of the spring carnival as he aims to give Godolphin a second Cox Plate victory in three years.

Cummings, who prepared 2022 winner Anamoe for the global racing giant, has enjoyed plenty of success with Broadsiding already this year.

The three-year-old has won five of his last six starts, including three Group 1s.

He is seeking redemption in Saturday's 2040m Group 1 feature at Moonee Valley after failing last-start in the Caulfield Guineas.

Cummings has been cagey all week about his tactics with Broadsiding, who will carry 49.5kg in the Australasian weight-for-age championship.

He admitted he would have preferred to be closer to the rails than barrier eight, but the awkward draw has not dampened his enthusiasm.

"I'm feeling full of anticipation," Cummings said.

"It's not a race where I'm going to beat my chest about being confident.

"It's too hard a race, really, but we're certainly delighted with the way Broadsiding is in himself.

"It's the ultimate test for him this spring."

Broadsiding sits fourth in betting behind Japanese favourite Prognosis, who brings impressive form to Melbourne.

The Hayes brothers' Mr Brightside and Ciaron Maher-trained frontrunner Pride Of Jenni have also attracted plenty of support.

Maher is seeking to add another Group 1 victory after claiming both the Caulfield Cup and The Everest last Saturday.

But the Cox Plate pre-race spotlight has been on another leading contender, Via Sistina, after a scare at track work on Tuesday when the mare threw jockey James McDonald.

Champion trainer Chris Waller altered Via Sistina's preparation in response to the incident and is thrilled with how she has presented for the race, shaking off concerns his leading fancy would not start.

"Tuesday morning I was hopeful to be in this position, but just absolutely everything has gone to plan (since then)," Waller said.

"You just never know what's around the corner and you don't try to get too far ahead of yourself."

Waller will also saddle up Melbourne Cup contender Kovalica in the Cox Plate but only rates the five-year-old gelding a top-five chance from barrier nine.

Champion jockey McDonald will chase his third successive Cox Plate win aboard Via Sistina for Waller, having piloted Danny Shum's Romantic Warrior and Cummings' Anamoe in the past two editions.

AAP