Blackcaps batsman Henry Nicholls will undergo further concussion checks after being hit by a Jofra Archer bouncer shortly before stumps on day two of the first test against England.
Nicholls, who was unbeaten on 26 at the close of play, was immediately checked by medical staff after receiving a blow to the helmet.
The 28-year-old stayed at the crease to guide New Zealand to 144/4, a first-innings deficit of 209 runs, after England had been dismissed for 353 after lunch.
Nicholls will need to be checked throughout Friday, and before play resumes on Saturday, pace bowler Tim Southee said.
"He'll be assessed later on tonight, and again in the morning, that's the protocol," said Southee, who sparked an England collapse in the first session and finished with figures of 4/88.
"He's shaping up all right at the moment, so fingers crossed he'll be right.
"He's a pretty tough character, so he'll rest up tonight, have a couple of Panadol and be back out there tomorrow."
New rules allow players to be replaced if they are ruled out of matches due to concussion.
If Nicholls is ruled out, Tom Blundell will come into the attack for New Zealand.
During the Ashes in August Australia's Marnus Labuschagne replaced Steve Smith after he was hit by an Archer bouncer.
The hosts had been well placed late on the second day before England's Sam Curran dismissed captain Kane Williamson for 51, reducing New Zealand to 127/4.
"I guess it would have been nice to be three down," Southee said.
"But we've still got some batting to come and hopefully a couple of good partnerships, and we can eke out some more runs."
Join us at 11am for live updates of the Blackcaps v England cricket test
Reuters
