Zoustar is the benchmark for three-year-old Australian sprinters but he could have a challenger in Canterbury Stakes rival Not Listenin'tome.

The pair's only clash so far in the Coolmore Stud Stakes resulted in a win for Zoustar over Not Listenin'tome.

They will meet again, this time at weight-for-age, in Saturday's Group One Canterbury Stakes at Randwick with Zoustar fresh from a spell and Not Listenin'tome having the benefit of a first-up win in Melbourne.

Not Listenin'tome was in his first racing campaign, having his maiden Group One test when runner-up in the Coolmore Stud Stakes.

Now more mature and experienced, he shapes as Zoustar's biggest danger on Saturday, a consensus reflected in early betting as they dominate the market.

Co-trainer Michael Hawkes says the chances of Not Listenin'tome turning the tables on Zoustar hinge on how much improvement the Chris Waller-trained colt has made.

"Zoustar is already at that (Group One) level," Hawkes said.

"Our bloke has improved. Whether Zoustar has improved again, that's the key."

Zoustar will be one of four runners for Waller along with comeback galloper My Kingdom Of Fife, Doncaster Mile winner Sacred Falls and outstanding mare Red Tracer.

Waller confirmed his quartet would all run with Red Tracer a chance to back-up a week later in the Coolmore Classic, depending on her handicap in the Group One fillies and mares race.

Guy Walter also has multiple runners in Appearance, Toydini and Streama.

Given the quality and depth of opposition, Waller can't single out a horse he is worried about the most against Zoustar.

"I fear every horse in a Group One race because obviously their trainers think they're going well enough to run," Waller said.

Victorian Speediness and front-runner Rain Affair round out the field.

Rain Affair needs to rediscover his best form and trainer Joe Pride believes he gets his chance from the inside gate.

"In this race the barrier probably doesn't matter as much. There's not a lot of speed to push him to the lead, he should get it comfortably," Pride said.

Zoustar has opened a $2.70 favourite ahead of Not Listenin'tome at $3.80 with Red Tracer next at $4.80.