New Zealand opener Martin Guptill will have to prove his fitness in order to be part of the T20I series against Australia, which begins on February 22 in Christchurch. The 34-year-old Guptill, who had missed the final two games of the Super Smash season with a hamstring injury, assembled with the squad in Christchurch on Friday even as Finn Allen continued to be in the 13-man squad a cover for him.

Guptill has not enjoyed particularly good form this summer, making just 46 in three T20Is against Pakistan in December before making three single-digit scores in his last four Super Smash innings. Uncapped 21-year-old batsman Allen, meanwhile, was impressive in the Super Smash, where he was the highest scorer overall with 512 runs in 11 innings, including six fifties.

"Finn's been in outstanding form and he's certainly an exciting talent," New Zealand selector Gavin Larsen said in a statement. "Martin's our incumbent opener and our highest T20 International run scorer, so we're backing him to do the job at the top of the order, but he will need to prove his fitness and it's good to know we have a ready replacement in Finn on stand-by."

Devon Conway, Glenn Phillips and Mark Chapman, who were all part of the T20Is against Pakistan, have been backed to continue in the batting line-up after impressing in their international stints. James Neesham, who underwent a finger surgery last month and returned to the Super Smash on February 6 after gaining fitness, is also part of the squad.

Larsen said this series would serve as a great starter to the T20 World Cup scheduled later this year in India. "Australia will provide a really stern test for our guys who I know will relish the chance to test themselves against the number two T20 side in the world. A five-game series also allows us to really nail down our game-plans and the way we want to play as we look ahead to the World Cup later this year.

"We've got a great rivalry with Australia. With the prospect of full houses up and down the country, I'm sure this series will be the biggest yet."

Squad: Kane Williamson (capt), Hamish Bennett, Trent Boult, Mark Chapman, Devon Conway, Martin Guptill (pending fitness test), Kyle Jamieson, James Neesham, Glenn Phillips. Mitchell Santner, Tim Seifert (wk), Ish Sodhi, Tim Southee, Finn Allen (stand-by for Guptill).

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