Argentina coach Santiago Phelan has recalled veteran centre Felipe Contepomi as one of two changes to his team to face Australia in the Rugby Championship.
Coach Phelan has replaced Santiago Fernandez with Contepomi and Horacio Agulla for Lucas Gonzalez Amorosino.
Argentina have lost all five of their matches this season in the four-nation championship, including a 33-15 loss on Saturday against New Zealand.
Last year was their debut season and they lost all of their matches.
Phelan did not say it outright, but many in Argentina see the Rosario test against the two-time World Cup champions as the potential droughtbreaker.
The Wallabies have only one win in the 2013 Rugby Championship - a dour 14-13 win against the Pumas in a wet and windy match at Perth - and have been struggling for cohesion under new coach Ewen McKenzie.
It will be tougher for the Wallabies on Argentine soil, playing in the city or Rosario - the birthplace of football star Lionel Messi.
"As always, we think we have our best 15 to start the game," Phelan said.
"Felipe and Horacio are two great players who bring a lot to the team. The team has been playing well and these two experienced players are important."
Phelan rejected suggestions he should have made more changes.
"We didn't make more changes because we think this is our best," he said.
Juan Martin Hernandez, Horacio Agulla, Marcelo Bosch, Felipe Contepomi, Juan Imhoff, Nicolas Sanchez, Martin Landajo, Juan Manuel Leguizamon, Pablo Matera, Juan Martin Fernandez Lobbe (captain), Patricio Albacete, Julio Farias Cabello, Juan Figallo, Eusebio Guinazu, Marcos Ayerza.
Agustin Creevy, Nahuel Lobo , Juan Pablo Orlandi , Manuel Carizza ,Benjamin Macome , Tomas Cubelli , Santiago Fernandez , Lucas Gonzalez Amorosino