The All Blacks are the only unbeaten side after the opening two rounds, but Nonu insist that his teammates will not be underestimating the Pumas.
"They defended well against the South Africans," Nonu told Sportal.
"I think they've got a few moves up their sleeves to pull out on Saturday.
"Sometimes if there are no holes you have got to make one really. You can't always go wide, you just have to bust it down."
Nonu will be starting at 13 following Sonny Bill Williams's move to Japan.