Rodrigo Roncero and Juan Martin Fernandez Lobbe were both injured in the win over Scotland last weekend which put Argentina on track for the World Cup quarterfinals and have been replaced by Marcos Ayerza and Leonardo Senatore.
In a third change to the forward pack, lock Mariano Galarza replaces Manuel Carizza.
Lucas Gonzalez Amorosino, who scored the match winner against Scotland, was elevated from the bench to the starting lineup at fullback and Juan Jose Imhoff was selected on the left wing. Gonzalo Cmacho and Martin Rodriguez were left out.
Mario Ledesma Arocena was selected for his 17th World Cup match, just one short of Frenchman Raphael Ibanez' record for a hooker.
Pumas captain Felipe Contepomi needs to score 18 points to break Hugo Porta's Argentine record of 590 international points. Contepomi needs 26 to become Argentina's top scorer at a Rugby World Cup, a record currently held by Gonzalo Quesada who scored 135 points.
Squad: Lucas Gonzalez Amorosino, Horacio Agulla, Marcelo Bosch, Felipe Contepomi (captain), Juan Jose Imhoff, Santiago Fernandez, Nicolas Vergallo; Leonardo Senatore, Juan Manuel Leguizamon, Julio Farias Cabello, Patricio Albacete, Mariano Galarza, Juan Figallo, Mario Ledesma Arocena, Marcos Ayerza. Reserves: Agustin Creevy, Martin Scelzo, Tomas Vallejos, Alejandro Campos, Alfredo Lalanne, Agustin Gosio, Martin Rodriguez.