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:
FedericoÃ0Â Serra; Horacio Agulla, Martin Gaitan, Manuel Contepomi,Ã0Â Lucas Borges; Juan Martin Hernandez, Agustin Pichot (capt.); Gonzalo Longo, Lucas Ostiglia, Martin Durand,Ã0Â Rimas Alvarez, Patricio Albacete, Omar Hasan, Mario Ledesma, Rodrigo Roncero.
Reserves:Ã0Â Alberto Vernet Basualdo, Martin Scelzo, Manuel Carizza, Augusto Petrilli, Nicolas Fernandez Miranda, Hernan Senillosa, Pablo Gomez Cora.
Barbarians' starting XV:
Anthony Floch,Ã0Â Aurelien Rougerie,Ã0Â Geoffroy Messina,Ã0Â Damien Traille,Ã0Â Rupeni Caucaunibuca, Lionel Beauxis,Ã0Â Jean-Baptiste Elissalde,Ã0Â Elvis Vermeulen,Ã0Â Thomas Lievremont (capt.),Ã0Â Thierry Dusautoir,Ã0Â David Auradou,Ã0Â Julien Pierre,Ã0Â Jean-Baptiste Poux,Ã0Â Benoit August, Laurent Emmanuelli.
Reserves: Michel Konieck, Benoit Lecouls, Gregory Lamboley, Matt Lievremont, Nicolas Morlaes, Benoit Baby, Nicolas Brusque.