Last year's Kewney winner Treasurethe Moment headed to Sydney to claim the Vinery Stud Stakes and the Australian Oaks before returning in the spring to win the Memsie Stakes at Caulfield.
In her first preparation, Sass Appeal has now won her past four starts and O'Brien is keen to give the filly a break to concentrate on the spring.
"Often with the three-year-old fillies you want to make hay while the sun shines against their own age, and sex, and make the best of what you've got before they turn four," O'Brien said.
"But I think this horse will measure up to the older horses. With that in mind, she's had a five start prep and I'm keen to give her a break and see her back here in the spring."
O'Brien said the Group 1 Empire Rose Stakes (1600m) at Flemington during Melbourne Cup appeals.
"The handicap races like the Sir Rupert Clarke and the Toorak Handicap are good options for her on the way through as well," he said.