Leinster outhalf Felipe Contepomi has not been released to play for Argentina against the French Barbarians in Biarritz on Saturday, the Argentine Rugby Union (UAR) said.
Contepomi, a key player for the Pumas at outhalf or inside centre, also missed the matches Argentina played against English club sides Northampton and Leicester.
The loss of Contepomi is a blow for Pumas coach Marcelo Loffreda, who arranged these matches while the top European countries were involved in the Six Nations championship for much needed match practice in a World Cup year.
"The absence of Felipe Contepomi is something that affects us a lot because it prevents us from seeing through all we had planned," said Loffreda.
With English clubs also not releasing their Argentine players, the Pumas face the French Barbarians with a 23-man squad mainly based in France plus six amateurs from Argentina and Contepomi's brother Manuel, who plays in Italy. France, are releasing 12 of their squad.
The French, who host the World Cup, open the tournament against Argentina at the Stade de France on September 7th.
The absence of Contepomi and the injured Federico Todeschini gives Loffreda another chance to play Stade Français fullback Juan Martin Hernandez at outhalf.
ARGENTINE SQUAD: Backs: Juan Martin Hernandez, Pablo Gomez Cora, Horacio Agulla, Lucas Borges, Hernan Senillosa, Federico Serra, Martin Gaitan, Manuel Contepomi, Agustin Pichot (captain), Nicolas Fernandez Miranda. Forwards: Gonzalo Longo, Martin Durand, Lucas Ostiglia, Rimas Alvarez, Patricio Albacete, Augusto Petrilli, Manuel Carizza, Rodrigo Roncero, Pablo Henn, Omar Hasan, Mario Ledesma, Martin Scelzo, Alberto Vernet Basualdo.