UPDATE 8.13AM: Key allrounder Mitchell Santner is out of the test series against England and faces up to nine months on the sidelines.

Santner, coming off a strong performance in the recent ODI series, has been cut down by a right knee injury, which has troubled him over the last few games.

He faces six to nine months on the sidelines which means he'll miss the Indian Premier League with the Chennai Super Kings in April, as well as the English county season for Derbyshire.

Following the England series the Black Caps don't play against until a tour to the UAE to face Pakistan in October.

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Black Caps selector Gavin Larsen gives update on Black Caps squad

A scan in recent days has shown that the defect had deteriorated further and will require surgery to be fixed. Santner will be operated on later this week, before beginning an extensive rehabilitation.

"On a personal level everyone feels for Mitchell. He's a popular guy in the changing room and he's well respected for the work he puts in for the side," said Black Caps coach Mike Hesson.

"Mitchell is a key player in all three formats for us, so we'll certainly miss him in the upcoming series. It's important though that he gets this fixed and we have him back for what is a big next 18 months for us."

That opens a door for Canterbury legspinning allrounder Todd Astle, while BJ Watling reclaims the wicketkeeping role from Tom Blundell.

Santner has taken 34 wickets from his 17 tests and averages a modest 25.47 with the bat since his debut in the pink ball test at Adelaide in late 2015.

His tidy left arm spin bowling is highly regarded, more for its controlling qualities than incisive penetration, while his batting, on the evidence of the ODI series, is growing in confidence.

Watling has been battling a niggling hip injury which forced him out of the two tests against the West Indies in December. In his absence Blundell made his presence felt with a maiden test hundred on debut at the Basin Reserve.

However Watling, who averages an impressive 38.05 with the bat, including six hundreds from his 52 tests dating back to late 2009, is a selectors' favourite. His left hip injury flared up before the start of the Plunket Shield.

He kept for the first time this season on February 17 but the selectors have seen enough from the last couple of Northern Districts' Plunket Shield games in which Watling has taken the gloves to figure he's ready to return. In those games he has scored 0, 45 and 4.

Watling will get another workout when a team camp for the bulk of the players takes place this week at Mount Maunganui. The players will assemble there tonight.

"BJ is a proven performer at test level for us and brings a lot to the group both on and off the field," said selection panel convenor Gavin Larsen.

"We've monitored BJ's progress over the past few months and it's great to see him back with the gloves for Northern Districts. Tom Blundell did a great job in BJ's absence and we'll keep working with him going forward.''

The rest of the 12-man squad is predictable, as it should be given it is a settled, and successful combination of late.

There are four seamers, with Tim Southee, Trent Boult, Neil Wagner and Matt Henry a solid chance to play as a quartet at Eden Park.

However Colin de Grandhomme's medium pacers could be a useful addition and make room for Astle to provide balance in what would be a third test appearance six years after his first, in Sri Lanka in 2012.

Opener Raval and bustling left armer Wagner will want to get up to speed smartly.

Unwanted in the marathon short-form programme this summer, they've had two Plunket Shield games since the end of the West Indies tests in mid-December as first-class preparation for the England tests.

Raval managed 0, 17, 20, 0 against Northern and Central Districts. Against that, the tall lefthander is averaging 44.5 from his nine tests, with six half centuries, three times stalling in the 80s.

Wagner took seven wickets against CD and Wellington in the last fortnight. His form against the West Indies was strong, 14 wickets at 18 apiece.

He is also New Zealand's best-ranked bowler in the game, at No 6. His role in the tests will be key.

New Zealand test squad

Kane Williamson, Jeet Raval, Tom Latham, Ross Taylor, Henry Nicholls, Colin de Grandhomme, BJ Watling, Todd Astle, Tim Southee, Neil Wagner, Matt Henry, Trent Boult.