Aidan O'Brien's assertions dual Derby winner Australia could be the best horse he has trained has raised expectations for his elder sibling Our Voodoo Prince.

The winner of all three starts since being imported to Australia, Our Voodoo Prince is high in early markets for the Caulfield and Melbourne Cups.

But trainer Chris Waller says the six-year-old has a long way to go to even get to those races.

By Kingmambo, Our Voodoo Prince is the first foal of eight-time Group One winner Ouija Board and like his mother, was trained in England by Ed Dunlop to win three modest races.

"Our Voodoo Prince used to be known as the son of Ouija Board but now he's known as Australia's brother," Waller said.

"He has to improve his rating to get to the Cups.

"He will trial on the first of August and again two weeks later.

"But where we start him off has not been decided. We have to have a good look at where he sits and what weight he might get in the Cups.

"That will determine whether he goes on a weight-for-age path or has to go in handicaps.

"He might start out on Warwick Stakes day (August 23) but that's not confirmed."

Some of the stable's established stars which are possibly heading to the Group Two Warwick Stakes will step out in a 900m barrier trial at Rosehill on Monday.

Group One winners Boban, Foreteller, Hawkspur and Sacred Falls will be joined in the heat by Kencella and Weary.

Waller believes dual Doncaster winner Sacred Falls can be a genuine Cox Plate contender.

He was returned to the stable after a spell at Waikato Stud where it was widely expected he would stand this spring.

But Waikato, which has a large share in the horse, decided to keep him racing for another season.