Lavanini, and Petti, both 25 years old, have been at the heart of Argentina's success this season, and the 100-kilo plus forwards are ones the All-Blacks will have to dominate if they want the win and the bonus point that will guarantee them title.
"Tomas Lavanini he's a physical player, he's got a good work rate, I saw him last week make a key tackle at a key moment so I guess possibly win the game for Argentina," Barrett said.
"Guido Petti is a good line-out forward and he's their leader so we'll be looking to, I guess, try and make them have a quiet night if possible."
