Unbeaten Diamonds braced for Silver Ferns

Australia's Steph Wood (centre) in actin against Malawi. Nigel French/PA Images via Getty Images

Lisa Alexander has selection headaches and a fresh injury concern to contend with as Australia's title defence gets set to ramp up at the Netball World Cup.

The Diamonds cast aside Malawi 74-25 on Wednesday (AEDT) to make it five easy wins from five in Liverpool, England, although Alexander was unimpressed that they finished with their most lacklustre quarter of the tournament so far.

It's created an edge before three far more challenging Tests that stand between them and a 12th world crown.

Their final preliminary match is against the also unbeaten New Zealand on Thursday before the medals are decided over the weekend, with England and South Africa most likely to be in the mix.

Alexander isn't looking past the Silver Ferns clash, pitting the teams that have contested the past five finals.

Even though the Trans Tasman rivals are both guaranteed semi-final berths, Alexander wants to maintain bragging rights over the opponents they've beaten in 11 of their past 12 meetings.

The loss was an 11-goal humbling in Hamilton last October, reminding the Diamonds that the Silver Ferns featuring veterans Laura Langman, Maria Folau and Casey Kopua can never be taken for granted.

"We've been watching them pretty closely the whole week, knowing obviously that both teams are going to be fairly evenly matched," Alexander said.

"They seem to be more fluent together. They seem to be happier together as a group, which doesn't surprise me with Noels (Noeline Taurua) as a coach."

Alexander said it's time to pinpoint her best seven players, having employed mass rotation against the tournament's lesser lights.

One certainty is Courtney Bruce, whose ruthless defence restricted Malawi to just five first-half goals and, eventually, their lowest World Cup score.

The goal keep finished with six gains, eight deflections and four rebounds although she was part of a team who eased off in the final quarter, which Australia won 13-11.

"We lost our way. A few basic errors that just shouldn't creep in but that's tournament play and we'll have to make sure we don't do that on Thursday," Alexander said.

"I'm kind of glad it's not perfect, we've got more work to do."

Bruce's defensive partner against New Zealand is uncertain after April Brandley missed the Malawi game with an ear injury. Alexander is "hopeful" the goal defence will be fit.

Paige Hadley's performances warrant selection in the top team although it will be hard to squeeze into a proven midcourt mix of Kelsey Browne, Liz Watson and Jamie-Lee Price.

Captain Caitlin Bassett and Gretel Tippett are the likely shooting duo although Caitlin Thwaites has enjoyed a prolific tournament.

Melbourne Vixens goal shoot Thwaites landed all 22 shots against Malawi to take her tournament tally to 134 from 136.