New Zealand great Neil Wagner has stunned everyone by retiring from international cricket ahead of the Test series against Australia.

The 37-year-old paceman was in the Black Caps squad for the two-match series beginning on Thursday in Wellington, where he was expected to resume his rivalry with Steve Smith.

Instead, he'll carry the drinks at the Basin Reserve and then walk away from the international stage.

Wagner said he decided to retire after a tough conversation with coach Gary Stead after their series win over South Africa, when Stead informed him he wouldn't be picked for the Australia Tests.

"It's been amazing to be a part of the Black Caps,'' Wagner said.

"To be able to represent New Zealand and to have the black cap on my head has been some of the proudest moments of my life.''

The South African-born paceman fought tears in an emotional press conference on Tuesday, thanking those in the Black Caps set-up and his family.

Wagner was a firm fan favourite for his courage, never more so than when bowling into the wind at Wellington.

In his last Test at the Basin Reserve, he took the wicket of England's Jimmy Anderson for a dramatic one-run win, completing one of the most memorable games of all time.

In 2020, Wagner won universal respect by bowling through the pain of two broken toes — hurt by a yorker while batting — to help New Zealand to a Test win on the fifth day over Pakistan.

Stead said Wagner would leave the game "as one of the greats".

"Not many people get to leave the game in the way that Neil has," he said.

"Neil's numbers are phenomenal, but I don't think we can underestimate his contributions to the team when the chips were down and he found a way to create a wicket.

Wagner was also part of the New Zealand side that won the country's first senior trophy: the inaugural World Test Championship in 2021.

He departs the Black Caps fifth on New Zealand's all-time wicket-taking list, with 260 scalps at an average of 27, and will play on in domestic cricket.

It is not yet clear who will replace Wagner in the Test side, with fellow quick Kyle Jamieson also missing the Australia series.

Stead has other concerns on availability for the first Test, starting on Thursday.

Devon Conway sustained a thumb injury during the T20 series and is seeing "a number of specialists" in a bid to play.

"He's had a bat in his hand a few times. It's not comfortable at the moment," Stead said.

"We are hoping that we can make a call tomorrow morning around where that sits."

In better news, Stead declared Rachin Ravindra — who has had knee soreness — available for the Test.

The 24-year-old sat out a team kick-about on the field, instead doing individual fielding drills while sporting strapping on his left knee.

AAP

ABC Sport is live blogging every ball of Australia's Test series against New Zealand from Thursday, February 29. Follow all the action from Wellington's Basin Reserve ground from 8:00am AEDT.

ABC Sport will also have ball by ball coverage on the ABC Listen App from 0845 AEDT each day, just look for the red cricket ball.