Among the backs, however, Loffreda has included Federico Serra and Horacio Agulla, looking to assess whether they are worthy of a place in his 2007 World Cup squad.
However, Leinster fly-half Felipe Contepomi will not able to join the Pumas as his club refused to release him.
"The fact that Felipe does not play is terrible for us," captain Agustin Pichot said, adding that he expects Saturday's game to be a real challenge for the team.
"The game will have the same demands as a Test match," he said.
"The Barbarians will not have the same pressure as they would have in an official Test because they play under the name of Barbarians, with the philosophy that name has.
"Saturday's game will be extremely tough."
Argentina's starting XV:
FedericoÂ Serra; Horacio Agulla, Martin Gaitan, Manuel Contepomi,Â Lucas Borges; Juan Martin Hernandez, Agustin Pichot (capt.); Gonzalo Longo, Lucas Ostiglia, Martin Durand,Â Rimas Alvarez, Patricio Albacete, Omar Hasan, Mario Ledesma, Rodrigo Roncero.
Reserves:Â Alberto Vernet Basualdo, Martin Scelzo, Manuel Carizza, Augusto Petrilli, Nicolas Fernandez Miranda, Hernan Senillosa, Pablo Gomez Cora.
Barbarians' starting XV:
Anthony Floch,Â Aurelien Rougerie,Â Geoffroy Messina,Â Damien Traille,Â Rupeni Caucaunibuca, Lionel Beauxis,Â Jean-Baptiste Elissalde,Â Elvis Vermeulen,Â Thomas Lievremont (capt.),Â Thierry Dusautoir,Â David Auradou,Â Julien Pierre,Â Jean-Baptiste Poux,Â Benoit August, Laurent Emmanuelli.
Reserves: Michel Konieck, Benoit Lecouls, Gregory Lamboley, Matt Lievremont, Nicolas Morlaes, Benoit Baby, Nicolas Brusque.