New Zealand's focus over the next week is trying to win back-to-back ODIs to protect a proud home record, but the Test series against South Africa will approach quickly and they have been boosted by Neil Wagner's progress after he suffered a fractured finger earlier this month.

Mike Hesson said that Wagner was "highly likely" to be available for the first Test in Dunedin, which starts on March 8, having healed well following the injury sustained when fielding off his own bowling for Otago at the start of February.

Wagner played club cricket on Saturday and came through "okay" according to Hesson. "He's done everything possible to ready for the first Test," Hesson added.

He has become a vital figure in New Zealand's Test attack, following the new-ball pair of Tim Southee and Trent Boult, with an unstinting work ethic and ability to ruffle batsmen with a regular supply of short deliveries.

In November he became the second-fastest New Zealand bowler to 100 Test wickets, behind only Richard Hadlee, reaching the milestone in 24 outings. Since the beginning of 2016, Wagner is New Zealand's leading Test wicket-taker with 51 wickets at 22.33 in 11 Tests.

However, New Zealand are covering their bases in case Wagner has any problem between now and the first Test. Matt Henry has been released from the one-day squad to play a Plunket Shield game for Canterbury at the Basin Reserve.

Henry has played one Test this home season, against Pakistan in Hamilton, where he claimed a single wicket and overall has an unflattering 17 wickets at 56.11 from seven matches. Due to being regularly with the national squad, Henry has only played one Plunket Shield game this season and in that he was pulled out during the second day for New Zealand duty.

"With Neil having had an injury we want to make sure that Matt is ready to go if required," Hesson said. "We also didn't think he'd be likely used in Hamilton therefore the opportunity to give him a first-class game."

If a reserve quick is required, New Zealand may also look at Lockie Ferguson who played in the third ODI. While he has proved expensive in ODI cricket, he has taken 18 wickets in four Plunket Shield matches. "I thought he bowled well enough to get two or three last night," Hesson said. "He's still developing, but he's certainly getting better."

BJ Watling, the wicketkeeper-batsman who required rest for a knee problem after the Test series against Bangladesh, has made his return to action for Northern Districts. The Test squad is likely to be named between the fourth and fifth ODIs.