Since 1991 when the tournament reverted from a round robin to a knockout format, after the group stage, Australia and New Zealand have contested six of the seven finals and all of the last five.

The two nations also contested the first five Commonwealth Games finals before England upset the Diamonds last year.

In the new world rankings issued this week, Australia remain top, with Jamaica jumping over England to second, followed by New Zealand and South Africa - who are coached by former Diamonds dual World Cup winning coach Norma Plummer.

The growing number of overseas players participating in Super Netball have also helped Australia's rival nations become more competitive.

England have six World Cup squad members playing in the Australian domestic competition, Jamaica five, South Africa three and New Zealand, two.

Australia's squad for the World Cup in Liverpool - running from July 12-21 - contains just three players from those that triumphed in Sydney four years ago.

With the 2019 tournament clearly shaping to be more than the traditional two-horse race, Australian captain Caitlin Bassett has a simple message to the nine World Cup rookies in her squad.

"Expect it to be hard," Bassett told AAP prior to heading to her third World Cup.

"We work our butts off here in Australia to get on a plane and know that we're playing against other countries who want it just as bad as us."

Bassett said it would be silly to not consider the Silver Ferns still a force to be reckoned with, pointing to the track record of coach Noeline Taurua.

She was looking forward to the Diamonds getting on with their business while much of the scrutiny falls on hosts England, after their surprise Commonwealth Games win.

"Just getting over there and doing our work and getting what needs to be done, and getting into that gold medal match," Bassett said.

Super Netball is being played either side of the World Cup, meaning domestic teammates will become international rivals for a couple of weeks.

Bassett understands that as well as most having shared a circle in recent months with England shooter Jo Harten for the Giants.

"I've been enjoying getting to know her both on and off the court, but we said goodbye after the last round," Bassett said.

"We're going to see her at the hotel, but we're enemies now."

The new World Cup format will have two preliminary stages before the playoffs.

Australia start their campaign on July 12 against eighth-ranked Northern Ireland, coached by former Adelaide Thunderbirds mentor Dan Ryan.

The Diamonds will also play first-stage preliminary matches against Zimbabwe (ranked 13th) and Sri Lanka (18th).

Australian Associated Press