Australian Horse of the Year Winx has scared off her rivals ahead of the Group One Caulfield Stakes.

Just seven horses have been nominated for Saturday's 2000m-race with one already declared an unlikely runner.

David Hayes, who trains in partnership with his son Ben and nephew Tom Dabernig, said the stable was likely to stick to its original plan and head to the Cranbourne Cup on Sunday with He Or She.

"We threw in a nomination because it's a small field," Hayes said.

"But it looks a two-horse race between her (Winx) and Black Heart Bart.

"It will be a good race but I think we'll stick to the Cranbourne Cup."

Hayes said the stable had endured a frustrating run in Group One races in the early part of the season, registering five placings.

"I think we're due," Hayes said.

"But this one may just be too tough."

He Or She has been placed in two of those Group One races, finishing third to Palentino and Black Heart Bart in the Makybe Diva Stakes before chasing home Black Heart Bart in the Underwood Stakes at Caulfield on September 24.

Winx has opened as $1.20 favourite as she attempts to extend her winning streak to 12.

She's a clear market leader over Black Heart Bart at $4.50 with Lucia Valentina and The United States on the third line of betting at $9.

Winx will be having her first try at Caulfield on Saturday which will be her final lead-up to the Cox Plate on October 22.

The Chris Waller-trained mare is not put off by small field sizes accounting for six and five rivals respectively in her two outings this campaign in Sydney.

Nominations for Saturday's Caulfield Stakes have been extended until 10am on Tuesday with final acceptances and the barrier draw for the Group One race on Wednesday.

Winx is the dominant Cox Plate favourite at $1.80 ahead of Sunday's Turnbull Stakes winner Hartnell at $4.