The Springboks won the second test 33-26 in Cape Town to square the four-match series at 1-1 at the weekend, but Roigard was a constant thorn in their side and created several scoring opportunities as well as crossing for a try himself.
It will be the same again on the Highveld in front of an expected crowd of over 87,000 at Soccer City in Soweto on Saturday, and Van den Berg says nullifying the threat of Roigard will come from making sure he does not have front-foot ball at the breakdown.
That means the Springbok forwards winning the contact battle, something they achieved in the first two matches.
"Cam is a very good player, but we just refer back to our system," Van den Berg said.
"If we are good enough and we get right what we want to get right, then he's going to have a difficult day behind a slow ruck.
"As a scrum-half, it's really difficult if your pack is going backwards. For us it's about putting pressure on them as a team, rather than focusing on him as an individual.
"We know what he's capable of, but it's more about shutting the All Blacks down than shutting Roigard down."
New Zealand's ability to find space in wide areas had the Springboks scrambling in defence in Cape Town and caused them to concede nine tries in the first two tests, unusual for the double world champions.
But Van den Berg says they trust their defensive system to limit that space this weekend in in Johannesburg.
"They are definitely the side that attacked the most that I've played against," he said.
"If you stay in the (defensive) system, it protects you. It wasn't perfect at times, but over the weekend (in Cape Town) it felt quite comfortable."
Van den Berg, 28, will start for a second time in a row on the replacements bench.
The fourth test in the series will be played in Baltimore in the United States on September 12.
