Ajaz Patel has been left out of New Zealand's Test squad for the upcoming two-match series against Pakistan despite having recovered from a calf injury. New Zealand instead leaned towards the all-round abilities of Mitchell Santner who retained his place in the squad.

In the injury-enforced absence of Colin de Grandhomme, Canterbury seam-bowling allrounder Daryl Mitchell too kept his spot but there was no room for Matt Henry who recently returned to action from injury and took a match haul of seven wickets against the touring Pakistan Shaheens earlier this week.

Kane Williamson will take over captaincy from Tom Latham after he missed the last Test against West Indies in Wellington to be with his partner Sarah Raheem for the birth of their first child.

Patel had been identified as a more attacking option, as part of a spin overhaul earlier this year, but his lack of recent game-time worked against him. The 32-year old's last competitive match was a Plunket Shield fixture for Central Districts in March.

"The toughest squad selection was clearly around the spinner," Gary Stead, the head coach, said in a statement. That basically came down to the balance of the side and with the four-strong pace attack going so nicely, we wanted to have a spinning allrounder as an option for that number seven position.

"It's really unfortunate for Ajaz, who has overcome his calf-injury, but the all-round ability of Mitchell Santner is our preferred option for this series. The fact Ajaz hasn't been able to have any game-time in the lead-up was also a concern for the selectors."

Williamson's comeback meant Devon Conway dropped out of the squad while Will Young remained as a reserve batsman.

The group is set to assemble in Mount Maunganui on Wednesday ahead of the Boxing Day Test which will start on Saturday. Having already beaten West Indies 2-0 earlier this summer, New Zealand will look for another clean sweep to boost their chances of making the World Test Championship (WTC) final which will be played in June 2021 at Lord's.

"The Test team have played some really good cricket of late and to have an opportunity to push for a World Test Championship final is truly exciting," Neil Wagner said.

The second - and final - Test will be played at the Hagley Oval in Christchurch from January 3 next year.