A record-equalling third Cox Plate is not the only milestone on the radar for Winx in the country's premier weight-for-age race.

If she can win at Moonee Valley on Saturday. Winx will become the first horse in Australian racing history to amass more than $15 million prize money.

Triple Melbourne Cup winner Makybe Diva holds the record with just over $14.5 million but the $1.8 million Cox Plate would take Winx's earnings to over $15.5 million.

Winx would also join retired unbeaten sprinting champion Black Caviar on 15 Group One wins.

The Chris Waller-trained Winx, who is striving to join Kingston Town as a three-time Cox Plate winner, is the $1.15 favourite to stretch her winning sequence to 22 in Saturday's 2040m-feature.

The final field will be declared on Tuesday morning, a couple of hours after Winx is scheduled to gallop at the public Breakfast with the Best trackwork session at Moonee Valley.

Winx will be the headline attraction at trackwork session held annually ahead of Friday night's Group One Manikato Stakes meeting and Saturday's Cox Plate program.

Three-year-old colt Royal Symphony is another Cox Plate hopeful due to work on Tuesday morning.

Tony McEvoy said he would work with a mate and have a more serious hit-out than he did on Saturday morning when he had a leisurely solo gallop at the track.

Trainer Kris Lees will gallop Doomben Cup winner Sense Of Occasion who holds a Cox Plate nomination.

"He'll work in the morning at Moonee Valley. We're still undecided," Lees said.

"He'll more than likely wait for the Cantala Stakes the following Saturday but we'll decide after tomorrow's gallop."

Manikato Stakes contenders In Her Time and Hey Doc are among the others scheduled to gallop.