Matfield, who will lead the Springboks against the Pumas to celebrate the 90th birthday of former South African president Nelson Mandela, believes the new laws are likely to favour his players who have already competed under the rules at Super 14 level.
"We know what to expect from them and have played them a number of times over the last few years. They are very physical up front. They like the rolling maul and the "pick 'n' go," Matfield said.
"The new laws could make the rolling maul a little more difficult for them. You can now pull the maul down and I'm not sure how much they will like that.
"They're a top team. They showed that when they reached the World Cup semi-finals last year and really surprised a lot of people."
Matfield insists that the Boks were using the match as preparation for their showdown with New Zealand a week later at Newlands.
He added: "It's going to be a good, physical battle. It is also a wonderful opportunity for us to focus on our own game and to work at the little things that we're still not doing right."