Roger James is certain Zonza's trackwork drubbing on Tuesday is not a reflection of her chances in the Group One Myer Classic.

Zonza was paired with Melbourne Cup-bound Silent Achiever on the course proper at Flemington and was left behind in the run to the line.

"If you saw her work early, she worked very upside down and wanted to do too much early (in the gallop)," James said.

But James came away from Thursday's training session with renewed confidence.

"She worked on her own this morning and it was as good a work as you wish to see. She did it totally differently."

Five-year-old Zonza made a winning start to her second Australian trip when taking out a Group Three race for mares at Caulfield on October 16.

James was going to run Zonzar last Saturday at Moonee Valley but took on board a recommendation from jockey Damien Oliver who won on Zonza at Caulfield and will ride her again on Saturday.

"That was at Damien's instigation really that I've decided to go this way," James said.

"He phoned me a couple of times saying he didn't think it was going to be overly strong and thought she would be competitive in it."

After doing his own homework, James decided to go to the Myer with a view to also backing up the following week in the Matriarch Stakes (2000m).

Zonza has only finished outside the top two placings in two of her 13 starts, with five wins and six seconds.

Red Tracer is a dominant favourite for the Myer Classic as she bids to win over a mile for the first time.

She is at $2.20 with TAB fixed odds ahead of Blazer Stakes winner Fire Up Fifi ($7) and in-form Sharnee Rose ($9) with Zonza at $12.