Jonah Shrock is studying history at Brown University in Providence, RI.
Argentina included five European-based players but omitted Juan Imhoff from their squad for next weekend's Rugby Championship match against New Zealand, the Argentinian Rugby Union announced.
The Argentine governing body has recently softened restrictions on individuals with contracts outside the country representing the Pumas.
Head coach Mario Ledesma picked four European-based players: fly-half Nicolas Sanchez, who is with Stade Francais, Toulon back-rower Facundo Isa, Bordeaux-Begles winger Santiago Cordero and Saracens prop Juan Figallo.
But Ledesma omitted winger Imhoff, 31, whose last international appearance came at the 2015 Rugby World Cup and plays for Racing 92 in France.
Argentina's 30-man squad to face New Zealand on July 20 in The Rugby Championship:
Forwards (16): Matías Alemanno, Agustín Creevy (capt), Juan Figallo, Ramiro Herrera, Facundo Isa, Marcos Kremer, Tomás Lavanini, Juan Manuel Leguizamón, Tomás Lezana, Pablo Matera, Santiago Medrano, Julián Montoya, Javier Ortega Desio, Guido Petti, Nahuel Tetaz Chaparro, Mayco Vivas
Backs (14): Emiliano Boffelli, Sebastián Cancelliere, Santiago Cordero, Tomás Cubelli, Jerónimo de la Fuente, Joaquín Diaz Bonilla, Felipe Ezcurra, Lucas Mensa, Manuel Montero, Matías Moroni, Ramiro Moyano, Matías Orlando, Nicolás Sánchez, Joaquín Tuculet