Looking to avoid a fourth consecutive loss after losing to the All Blacks 17-19 in the centenary Test in Townsville last weekend, Nienaber said: "There's an excitement that the bubble is almost at an end, but the challenge for us, is to ensure we have two feet in Australia."
The Springboks have been in a Covid-19-induced bubble since before their July series against the British & Irish Lions.
"I've been in Super Rugby teams where at the back end of a long tour the team has one foot in South Africa and one in New Zealand or Australia.
"It's critical to be in the now, and it takes a while getting used to the bubble. It took one back to the levels of hard lockdown that we had in South Africa.
"It's not an excuse, but sometimes, on forgets how it was sitting in your house, and that's how things were for 14-15 weeks," he said.
Nienaber said their run of losses to Australia and the All Blacks hadn't derailed South Africa from their post-World Cup plans, but it had set them back.
"When I was appointed in January last year, the two big things we aimed for was the Lions' series and the World Cup," he said.
"Those are the big ones we had to put our focus on, especially the Lions series because it's once in a lifetime.
"We looked at evolving last year, and we had to play result rugby against the Lions. We're still building up to where we were in 2019.
"What the last three games have shown me is our DNA, where we need to improve to get the results that suit our players.
"If we could get more Test experience into our group next year, we'd love to do that," he said.
A win on Saturday would be a boost for the side.
"Everyone in our team realises the importance of finishing the Rugby Championship on a winning note.
"We have no doubt that if we can build on the strong points of our game last week, and improve further on the execution of our gameplan, we can get the desired result," he said.
Any change in South African strategy would depend on New Zealand's approach, he said.
"If New Zealand change the way they defend, the way they do things and give us space in a different area of the field, we'll take it.
"If they load the front line with 14 defenders, and one at the back, the space will obviously be at the back. Adapting to the picture they paint for us will be the key, so it will depend on where they give us space," he said.