Star filly Mystic Journey is ticking along nicely as the countdown continues to her return to the races for a campaign aimed at the Cox Plate.

The Australian Guineas and All-Star Mile winner has been back in work in Tasmania for almost seven weeks, with trainer Adam Trinder planning to give her a final start as a three-year-old in the Bletchingly Stakes at Caulfield.

The Bletchingly (1200m) on July 27 and the Group One Memsie Stakes (1400m) at Caulfield on August 31 will tell Trinder whether Mystic Journey remains on course to the Cox Plate, for which she is favourite.

"That is my hope," Trinder said.

"She would obviously have to come back, flourish and improve, which I believe she has flourished. So we'll see on race day as to whether she has improved or not.

"We've obviously got the Golden Eagle as an option but these first two runs will tell us whether we're set in stone to move forward towards the Cox Plate. But that's definitely my hope."

The $7.5 million Golden Eagle (1500m) is a new race for four-year-olds at Rosehill on November 2.

Trinder said Mystic Journey was up to doing even-time work on the training track.

"She is in really good order," he said.

"Her action is nice and fluent. Her appetite is good. She's really happy so I'm really happy. At this stage all roads lead to kicking off in the Bletchingly."

Trinder believes starting Mystic Journey's campaign in the Bletchingly affords him the time to space her races.

"It gives her four runs leading into a Cox Plate without taxing her in any regard," he said.

"She operates best off three plus weeks between runs.

"Whilst nothing is set in stone, it's a very similar template to what we used last year. She kicked off in the back end of July last year in Melbourne and went through and won the Group Two (Fillies Classic) on Cox Plate day."

Trinder is comfortable with the physical development Mystic Journey has made heading into her four-year-old season.

"She has deepened down through the shoulder and really thickened out through the hind quarter," he said.

"I probably didn't appreciate it as much when she returned to the stables because she spelled at my farm and I was still seeing her every day.

"But the comment from the girls around the yard, they've really noticed a physical change in her in a short period of time. So that gives me good solace moving forward."