Trainer Chris Waller says champion racemare Winx will most likely be switched to Melbourne to continue her Cox Plate campaign.

Waller announced on Wednesday he has pencilled in the Group One Turnbull Stakes at Flemington on October 7 as the next start for Winx.

On track for a third successive Cox Plate victory, Winx stretched her winning sequence to 20 in claiming the George Main Stakes at Randwick last Saturday.

"The sole reason (for the Turnbull) as the most likely option is simply based on the timing of the current program," Waller said.

A Turnbull Stakes start would give Winx three weeks since her George Main win with the same time between races until the Cox Plate at Moonee Valley on October 28.

"As has always been the case, I will continue to be guided by the horse and what I feel is best for her when planning her racing preparations," Waller said.

Waller had been tossing up between the Turnbull and the Group Three Craven Plate at Randwick on October 14 as the next possible appearance for Winx.

After consulting with jockey Hugh Bowman, Waller will tinker with Winx's gear for the Turnbull.

"It is my intention to remove the ear muffs from her raceday gear for her next start as Hugh and I don't feel they are required," Waller said.

Winx is a $1.50 favourite to join Kingston Town as a three-time winner of the Cox Plate, Moonee Valley's flagship event regarded as Australia's weight-for-age championship.

Bowman agreed a three-week gap was justified.

"She appeared lethargic to everyone that watched in the early stages of the race (George Main Stakes) the other day. But it was a very fast time.

"I think that may have added to Chris's option to go the three weeks between runs.

"I think it's (Turnbull) an ideal race, Sunline did it on her way there, we'd like to think Winx could too."