Devon Conway remains a doubt for the opening Test against Australia in Wellington next week and will see a hand specialist to ascertain the extent of the damage he suffered to his left thumb during the second T20I at Eden Park.
Conway suffered the blow in the second over of the match when he took a sharp delivery from Adam Milne down the leg side. He was briefly treated on the field before deciding not to continue and Finn Allen took the gloves for the rest of the innings.
Conway went to hospital for x-rays and did not bat during New Zealand's chase. He was cleared of "an obvious fracture to his left thumb" but was ruled out of the final T20I and returned home to Wellington on Saturday for further assessment.
"There is a little bit of concern because we are not 100% sure yet exactly how it's going to respond over the next three or four days," New Zealand coach Gary Stead said. "[We've] still got a little bit of time and at the end of the day think it will come down to pain management and what he can do in that space around making sure he feels comfortable at the crease.
"It's still a little bit unknown. Last night he had some strange things going with his thumb, it was clicking a little bit…but at this stage he has been cleared of a break which is great. He'll see a hand specialist tomorrow in Wellington and we'll find out more then."
There was a more encouraging prognosis for Rachin Ravindra after he sat out the second T20I with knee soreness. He remains with the squad but is unlikely to be risked in Sunday's match with an eye on the Test series.
"Not as much concern around Rachin," Stead said. "He does have a bit of a niggly left knee. Think it's unlikely he will play tomorrow with the Test matches in mind, but we are very confident that he will still progress well to be right for that first Test match. He's slightly better today than what he was yesterday which is the encouraging signs we want."
Conway is penciled in to open the batting in the Test series while Ravindra is also a lock for the XI after he converted his maiden Test hundred into 240 against South Africa recently.
If Conway is ruled out, Will Young would be his likely replacement at the top of the order. Young is the reserve batter in the Test squad and can cover a variety of positions. He came into side against South Africa in Hamilton as a middle-order replacement for Daryl Mitchell but can also opening the batting. Conway does not keep in the Test side with that role belonging to Tom Blundell.
Tim Seifert, who himself was initially ruled out of the T20I series with an abductor injury, has been called back into the squad as Conway's replacement for the last match of the series while Jacob Duffy has been added as fast-bowling cover. One more batter will be added after the conclusion of today's Ford Trophy final in Christchurch.
Ahead of the first Test, both Mitchell (foot) and Matt Henry (hip) are progressing well in their recoveries. "Very confident they'll be good to go," Stead said.
Kane Williamson's partner, Sarah, gave birth to their third child, a girl, earlier this week which ensures he will be available for the Test series having missed the T20Is.
In terms of the T20I series, Stead was not overly concerned by New Zealand falling 2-0 down given the opening game went down to the last delivery then Conway's injury meant they had to reshuffling the batting order in Auckland.
"T20 cricket is pretty fickle, and that first game could have easily gone the other way," he said. "You move on very, very quickly. We want to take the learnings and make sure we put them into practice, but there's still a lot of good things that have come out of the last two games.
"Ben Sears, for example, I thought was fantastic, a young guy early in his career. Thought Lockie Ferguson in the two games has bowled superbly well and looked somewhere back to near his best which is really exciting to see.
"We are pretty realistic. Yes, we didn't get the result we wanted last night but there are a number of guys who will come back into our side as well around the World Cup which will make a big difference in terms of experience."