Supersub Caitlin Bassett is ready to step up again as Australia keep New Zealand guessing over captain Catherine Cox's role in the second netball Test.

The Diamonds must win at Adelaide Entertainment Centre on Wednesday night to keep the three-Test series against their arch-rivals alive after going down 49-48 in a thriller in Perth.

And the big pre-match question will be whether rookie head coach Lisa Alexander persists with starting her veteran skipper Cox as goal shooter after she faltered in game one.

Just as she did in the world championship final in July, 23-year-old Bassett turned a desperate situation around after replacing a struggling Cox at halftime.

In the world championship decider in Singapore, she shot 24 goals at 90 per cent including the match-winner in the last second of overtime.

In Perth on Sunday, Bassett did all but secure victory, nailing 19 of 21 shots as the Diamonds came up just short after the usually reliable Cox managed just 14 of 23.

Alexander gave no indication of her plans for 35-year-old Cox and Bassett on Tuesday, though previous supportive comments suggested she may keep faith with the veteran, at least initially.

Bassett says she'll be ready to face the Silver Ferns if called, whether as sub or starter.

"I love playing against New Zealand, they are always tight games, they are always nail biters," said Bassett.

"I am extremely keen, going down by one goal is obviously what the Kiwis felt like at world champs, so I just want to get back out there and pull out a win for us."

"Hopefully we will be able to get more than a goal ahead of them for the sake our own hearts and the hearts of the crowd."

As ever, veteran Silver Ferns goal shooter Irene Van Dyk holds the key for her team after nailing 27 goals from 29 attempts on Sunday.

Netball New Zealand high performance director Tracey Fear said the Silver Ferns were injury free apart from the usual "body-clash type of niggles".

"Whenever you play Australia, you are not confident of the outcome but we are confident in our preparation," she said.