Heatherly has already won the first of three planned Moonee Valley 1000m sprints and is favourite to add another in the McEwen Stakes.
Co-trainer Simon Zahra is adamant the Group-winning sprinter has improved since her first-up win in the Listed Carlyon Stakes at Moonee Valley.
But he admitted the four-year-old would also have to work harder from the outside barrier in Saturday's Group Two McEwen Stakes to cross to her usual prominent position.
Another strong showing from Heatherly on Saturday will set up a shot at the Group One Moir Stakes (1000m) at Moonee Valley later in September, a race slated for star sprinter Chautauqua's return.
"She has come right on, which is good," Zahra said.
"But she's going to have to do a bit of work from that gate, that's for sure."
Zahra says Heatherly's winter coat has dropped and he expects Saturday's race to bring her on even more.
"It's been a faultless preparation. She'll continue to improve and her history tells us she gets better throughout her campaign," Zahra said.
"If she goes well on Saturday we'll head to the Moir and be third-up into that race."
Heatherly has barrier 10 in a field which includes last-start Sir John Monash Stakes winner Wild Rain, last year's Schillaci Stakes winner Alpha Miss, Robert Sangster Stakes runner-up Sheidel and Godolphin-owned four-year-old Furnaces.
Four-year-old Heatherly, winner of the Group Two Rubiton Stakes and placegetter in the Oakleigh Plate last campaign, is at $2.90 ahead of Furnaces at $5.50, while Sheidel and Wild Rain are at $6.
G2 - The Totepool National Spirit Hurdle Race (class 1)
G2 - Paddy Power Johnstown Nov Hdle
Grade B - Nas Na Riogh Nov Hcp Chase
G3 - Paddy Power Newlands Chase
G1 - Queen's Silver Jubilee Cup