A thoroughly outplayed New Zealand received a glimmer of hope on Sunday that Ross Taylor and Trent Boult could be fit for the third Test after announcing the pair will rejoin the squad.
But batting coach Craig McMillan cautioned there was still no guarantee that either batsman Taylor or strike bowler Boult would play against South Africa when the third and final Test starts in Hamilton on Saturday.
As South Africa wrapped up the second Test inside three days in Wellington on Saturday to lead the series 1-0, it was evident to New Zealand how little depth they had when two of their few stars were absent.
Taylor tore a calf and Boult suffered upper leg soreness during the drawn first Test in Dunedin.
The prospect of Boult returning looked promising after he comfortably went through a short practice session but Taylor's fitness was unclear.
"You can't take players into a Test against South Africa who aren't fully fit," McMillan said.
"I haven't spoken to (Taylor) for a couple of days but I'm sure he's keen. He loves playing there and he's done well in recent times."
Taylor has scored four of his 16 centuries in Hamilton including an unbeaten 102 in his last outing there against Pakistan in November.
New Zealand captain Kane Williamson did not try to hide his frustration at what he called a "very, very poor" effort from his side when they went from being in command at lunch on day two to be soundly beaten five sessions later.
"The frustrating part for us is when you play a side like South Africa, and you do have them under pressure, you have to keep them there," he said.
"That's the challenge and you have to do it for a long period of time, and if you don't, they can change the shape of the match quite quickly. We certainly let it slip very quickly and it went bad quickly."
McMillan described the performance as "unacceptable" but said that did not mean there would be wholesale changes to the line-up.
"We've got the best players in New Zealand in the squad," McMillan said.
"They certainly showed in Dunedin that they are good enough to play well and compete. Yesterday they didn't stand up. Yesterday was a terrible day.
"To lose within three days is unacceptable and the group is hurting and disappointed."
What hurt Williamson was to see South African spinners Keshav Maharaj and JP Duminy take 12 of the 20 wickets on the pitch prepared to favour the quicks.
"But on a surface that was far more suited to the seam bowlers, to lose that many wickets to spin is disappointing and something we need to address," he said.
"We do need to play that a hell of a lot better."