Black Caps pace-bowler Will O'Rourke has been ruled out of this week's second test against Australia in Christchurch, while batter Devon Conway needs surgery on his thumb.
O'Rourke picked up a hamstring strain while bowling on day three of the first test in Wellington, which Australia won by 172 runs inside four days, and will require at least two weeks of rest and rehabilitation.
Uncapped Wellington pace-bowler Ben Sears will replace O'Rourke in the 13-man squad and will join the team in Christchurch when they assemble on Tuesday.
The 26-year-old has 58 First-Class wickets from his 19 appearances at an average of 27.
Meanwhile, opener Devon Conway, who missed the first test, will this week undergo surgery on the left thumb he damaged during the T20I series against Australia.
Following several scans and specialist advice, the decision was made to operate on Conway with a likely recovery period of at least eight weeks.
Canterbury batter Henry Nicholls, who was called in as cover for the first test, will stay with the squad for the second, which starts at Hagley Oval on Friday.
Black Caps coach Gary Stead wished Conway a speedy recovery.
"We're all feeling for Devon," he said.
"He's a massive part of the Black Caps and we're going to miss his presence both on and off the field.
"We wish him all the best for his surgery and we will be there to support him as he begins his recovery."
Stead said Sears was ready for Test cricket.
"Ben's a young bowler with a quality skill set," he said.
"He bowls with genuine pace and gets good bounce which is always a great asset in red ball cricket.
"We've been really impressed by his performances for the Black Caps white ball cricket this summer and believe he can make the step up to the Test arena if called upon.
"It's disappointing for Will to be ruled out, especially after making such a strong start to his international career.
"He's shown he's a player with huge potential and at 22-years-old we're hopeful we will see a lot more of him in the Black Cap."
Neil Wagner has been released from the squad as planned.