Chris Waller concedes he is training Winx with an added sense of responsibility as the Cox Plate winner returns to racing as an overwhelming Apollo Stakes favourite.

Winx has taken over as Australia's best racehorse and also ranks as the nation's most popular.

And it's not lost on Waller that Winx's reputation is on the line when she resumes at Group Two level at Randwick on Saturday.

Waller is mindful of what lies ahead but is certain Winx is in the right form to justify her odds-on quote for the Apollo while leaving enough to work with to have the mare at her absolute best for $4 million Queen Elizabeth Stakes in April.

"I feel it's important to try and keep her winning," Waller said.

"And at the same time it's important not to do anything different than we normally do to ensure she's there at the end of the campaign as well."

Thoroughbred people like to say how their racehorses return to training bigger and better than before.

In Winx's case, Waller is happy to announce the mare is a bigger racehorse than one which went unbeaten during a three-start spring campaign.

But it might be wishful thinking to say she has improved.

"You can't say she has come back better. She's won a Cox Plate by four lengths. You can't go any better than that," Waller said.

"We've got to make sure she comes back as good as that."

If it wasn't for an unplaced run in the Light Fingers Stakes at the corresponding meeting last year, Winx would take an unblemished first-up record into the Apollo in which she is one of five Group One winners resuming.

The most breathtaking of her three first-up wins came in the spring when she gave away an impossible start before getting a photo-finish result in the Theo Marks Stakes at Rosehill.

Odds-on favouritism in the Apollo has been reserved for an elite few and at $1.55 bookmakers are rating Winx on the same level as Sunline and Lonhro, both of whom won the weight-for-age race at $1.24 and $1.30 respectively.

With the exception of second favourite Solicit ($4.80), Winx's opposition comprises handicap stayers expected to figure much later in the autumn carnival.