Central Districts batsman George Worker has replaced Tim Southee in the Black Caps squad for the first test against the West Indies in Wellington.
Southee is unavailable for the match, which starts at the Basin Reserve on Friday, as he awaits the birth of his child.
New Zealand selector Gavin Larsen said Worker, who has never played a test, provides extra batting cover.
"Obviously there are things more important than cricket and we support Tim and his decision to stay with his family right now.
"George will join the test squad for the first time on the back of his form in First Class cricket over the past couple of seasons."
Worker has played four one-dayers and two Twenty20s at senior international level since his Black Caps debut in August, 2015.
The 28-year-old left-hander has played 82 first-class matches between the New Zealand A, Central Districts and Canterbury teams, with an average of 29.63.
He has seven centuries and 21 fifties at first-class level and was part of the New Zealand A team's tour to India in September and October.