Injured scrumhalf Gonzalo Bertranou has withdrawn from the squad to face England in the second test in San Juan on Saturday, the Argentine Rugby Union said.
Bertranou, 31, was taken off hurt during Saturday's 35-12 defeat by England at La Plata, replaced by debutant Simon Benitez Cruz at the start of the second half.
The details and extent of his injury were not disclosed.
Coach Felipe Contepomi has called up Mateo Albanese as his replacement and now has three scrumhalves in the squad for the second test, with Benitez Cruz and Agustin Moyano also competing for a place in the team.
Argentina have also called up Guido Petti, who can play at lock or flank, and utility back Geronimo Prisciantelli to strengthen their squad for the match, as well as the clash against Uruguay in Salta on July 19.
Petti arrives after competing for Bordeaux-Begles in the France Top 14 final against Toulouse on June 28, while the uncapped Prisciantelli is called up from Zebre in Italy.