At the forefront of his considerations will be whether to start 2019 World Rugby player of the year Pieter-Steph du Toit.
The blindside flanker has suffered injuries since his outstanding play in South Africa's 2019 Rugby World Cup win. He suffered a career-threatening leg injury in 2020 and, while recovering to play against the British & Irish Lions in 2021, he then suffered a shoulder injury in a late tackle in the second Test of the series.
He played only three Tests of the 13 South Africa played in 2021.
He was back on the field for his Japanese club Toyota Verblitz in January this year, and while playing in South Africa's first two Tests against Wales earlier this month, he looked well short of his best form. He could play the two All Blacks Tests off the bench and start in games against Australia and Argentina.
One report on iol.co.za said, "His trademark high work-rate was missing from his game and he wasn't prominent as a ball-carrier or relentless tackler."
Nienaber faced a difficult choice, but leaving him out might be the right call at this time of the season, the newspaper said.
"Much like captain Siya Kolisi, du Toit seems to be the type of player that needs to get through a few games to get up to speed again," it said.
One possibility was that No8 Jasper Wiese, who played in the position in two Tests against Wales, could be moved to blindside flank allowing Kwagga Smith to play No8.
Wiese's ball-carrying into opposing defences would suit the blindside role, while Smith could lift the tempo in games and was a threat at breakdowns.
No8 Duane Vermeulen and utility back Frans Steyn were named in the squad for the series. They will be assessed by coaches but, as neither has played for two months, it is unlikely they will be considered.