The draw for the 2023 Rugby World Cup was made on Monday and has South Africa drawn in a 'pool of death' alongside Ireland and Scotland.
New Zealand and France are in the same pool with the loser of their game likely to face South Africa, if they qualify top of their pool, in the quarterfinals.
But Nienaber said South Africa's immediate concern would be qualifying from their group.
"If you look at our pool and the quality that will be present, then it probably wouldn't be the right thing to start focusing on quarterfinals and knock-out rugby," he told media after the draw.
The All Blacks and South Africa met in a pool game on the first weekend of the 2019 Rugby World Cup in Japan, with the third-placed All Blacks winning and inflicting the only defeat on the eventual World champions at the tournament.
Nienaber said, "You'll have to be pretty clued up and on top of your game to get out of the pool. The nice thing about it is that there are no two ways about it.
"It's quite strange to think that either South Africa, Ireland or Scotland might not make it into the play-off stages. It's going to be a tough pool, but I'm very excited," he said.
By a fluke of the draw process, the game with Ireland will be a first for South Africa at a World Cup. They have previously played Scotland twice.
But Nienaber said with the draw now completed the task would be to concentrate on the build-up during the next three seasons.
"You'll need a proper squad with good experience to get out of the pool. That's the immediate aim."
An important step in gaining that experience will be next year's series against the British & Irish Lions and before that he would like to have more international rugby for his players.
"We've got our local game up and running again, so the next focus is getting international opposition," he said.
Nienaber said he had no regrets about South Africa's withdrawal from the Rugby Championship. This was despite Argentina performing well on minimal preparation – the issue that led to the Springboks' non-participation.
"I still believe we made the right decision. There were different lockdowns for different countries and ours was quite extreme.
"From a player safety point of view, it was definitely the right call. But we'll now have to be creative in preparing us for international rugby next year. The guys are working hard behind the scenes in getting that going," he said.