Argentina prop Rodrigo Roncero has been held back from joining his countrymen for the Test match against South Africa in Buenos Aires at the weekend by his club Stade Francais, who need him for the Heineken Cup encounter with Ulster.
He will probably be the first of many European players to reamin in France and, in Felipe Contepomi's case, in Ireland.
Stade are already short of props Pieter de Villiers and Sylvain Marconnet, injured in the hectic struggle with New Zealand on Saturday night.
Originally, Max Guazzini, the owner of Stade Français, had said that his Argentinian players were free to play for the Pumas.
Scrum-half Agustín Pichot and full back Juan Hernández will stiil travel to Buenos Aires, but the propping crisis has prevented Roncero from joining them on the plane.