Trainer Lee Freedman has called on Singapore-based Glen Boss to ride Tom Melbourne in the Group One Australian Cup.

Tom Melbourne will be one of two runners in Saturday's 2000m weight-for-age feature at Flemington for the Lee and Anthony Freedman stable along with well-performed import Exospheric to be ridden by Damien Oliver.

Boss won three consecutive races on Tom Melbourne last season including the Albury Cup in March 2016 before he moved to Singapore.

He has returned to ride Tom Melbourne in two races since, with the horse unplaced in last spring's Naturalism Stakes and second in the Lexus Stakes at Flemington.

Tom Melbourne was ridden by Joao Moreira in the Peter Young Stakes on February 25 when he finished ninth.

"It was a nothing run because he grabbed him out of the gates and he just over-raced at the tail of the field," Freedman said.

"His previous run was very good, so we'll get Bossy back to ride him and we'll see how we go.

"He (Boss) has got a good understanding of the horse. He's a tricky horse in that you can't really swap riders on him all the time, because they just don't get him.

"It's no-one's fault, it's the horse, but Bossy understands him."

In his first Australian start in the Caulfield Cup in October, Exospheric finished third and showed he was on target for the Australian Cup with an eye-catching sixth first-up in the Peter Young.

Exospheric was a Group Two winner in England and Freedman was thrilled with the horse's last 200m in the Peter Young when he closed strongly.

"Exospheric was very good first-up and he'll be suited by the big stretches of Flemington," Freedman said.

"He ran the fastest sectionals of the race so that was encouraging."

Exospheric is at $7.50 for the Australian Cup while Tom Melbourne is at $15.

Humidor is the $4 favourite ahead of Jameka at $4.40.

"I think Exospheric is the better performed horse," Freedman said.

"But the other horse has a bit of X-factor if he runs his race the way he can run his race."