The majority of the group ply their trades in France with that league providing 16 of the Pumas' squad.
Six players are based in England while there are also representatives from the Scottish and Irish leagues.
Argentina's first match is at home to South Africa on November 5 in Velez Sarsfield's Jose Amalfitani stadium, and a week later Loffreda's side face Scotland in Edinburgh.
The Pumas then meet Italy in Genoa on November 19.
Argentina squad: Mario Ledesma, Gonzalo Longo, Martin Scelzo (all Montferrand), Federico Todeschini (Beziers), Manuel Carizza, Federico Martin Aramburu (both Biarritz), Manuel Contepomi, Bernardo Stortoni (both Bristol), Santiago Sanz (CASI), Augusto Petrilli (CSBJ Rugby), Francisco Leonelli (Edinburgh Gunners), Pablo Bouza (Harlequins), Nicolas Fernandez Miranda (Hindu), Felipe Contepomi (Leinster), Juan Martin Fernandez Lobbe (Liceo Naval), Juan Manuel Leguizamon (London Irish), Martin Durand (Montpellier), Patricio Albacete (Pau), Martin Schusterman (Plymouth Albion), Eusebio Guinazu (Rugby Club Toulonnais), Gonzalo Tiesi (SIC), Carlos Ignacio Fernandez Lobbe (Sale Sharks), Lucas Borges, Pablo Henn, Juan Martin Hernandez, Agustin Pichot, Rodrigo Roncero (all Stade Francais), Omar Hasan (Toulouse).