The star Tasmanian mare has barrier six but will jump from barrier five if the third emergency doesn't get a run.

"Barrier six sits well ... it gives you options but I expect she'll roll forward and settle in the first half of the field," Trinder said.

"If you draw inside four you need a bit of luck early and if you draw wide you can get caught up in that mad urgency to get across.

"From barrier six, you're also one of the last horses to be loaded so you're not standing in the stalls for too long."

Under Cox Plate rules, the connections of each runner got to select their own barrier in the order that their horse's names were drawn from a barrel.

Mystic Journey was the second horse drawn and, with only barrier three already taken, owner Wayne Roser had no hesitation in taking six.

"We discussed it at length on Monday night and decided six or seven would be our preferences," Trinder said.

Trinder said Mystic Journey was in perfect order for her bid to become Tasmania's first Cox Plate winner.

"She had a lovely gallop in Launceston on Saturday morning which topped her off nicely," the trainer said.

"I did have to diversify (her training) after she had such a soft run in the Turnbull Stakes but I'm very happy with the way she's progressed."

Mystic Journey shortened from $7 to $6 with tab.com.au after the draw.

Japanese mare Lys Gracieux is an easing favourite ($3.40 to $3.60) after drawing wide.