"We're still investigating Devon's thumb at the moment," Stead said. "He's seeing a number of specialists at the moment. You won't see him at training today. But we are hoping that we can make a call tomorrow morning around where that sits. He's had a bat in his hand a few times. It's not comfortable at the moment. But, as I said, we're still investigating exactly what's going on in the thumb. We've had a number of different specialists look at it."

Stead confirmed that he would need to see Conway hit some balls in the nets before clearing him to play.

"He's going to get more scans later today and more expertise on it," Stead said. "We obviously want Devon to play. He's a key person I think in our batting order. His record speaks for itself. So we want to give him every chance of being available."

Mitchell will return to his spot at No. 5, meaning Will Young will likely make way unless Conway is ruled out, in which case he will open the batting alongside Tom Latham.

"I think in hindsight, we probably got that wrong the way that the pitch did behave," Stead said. "We've certainly got Mitch Santner here as that option and we'll certainly consider him as well."

Skipper Tim Southee, Matt Henry and Will O'Rourke look likely to be the trio of quicks with Scott Kuggeleijn the only other fast-bowling option in the squad. The pitch had a typically green look to it two days out from the first Test but those who have been to the middle said it looks very good and firm underneath despite the covering of live green grass.

New Zealand have not beaten Australia in a Test at home since 1993 and have not beaten them anywhere since 2011, but Stead said the series represents an opportunity to improve their record against their neighbours.

"We don't play Australia that often, which is strange considering that they're just across the Tasman there," Stead said. "But, look, they always set the benchmark and are current world Test champions and they are that for a reason. They're a very good side. But that's our opportunity. And that's for us to go out and I guess show our wares and we're certainly looking forward to the challenge that is ahead."