The 19-year-old number 10 earned the call from coach Sergio Batista after Gimnasia midfielder Luciano Aued dropped out through injury, as confirmed on Friday morning on the Argentine FA's official website. The Lobo man suffered a pelvic injury and was forced to drop out of the squad.
Lamela's River team-mate Jonathan Maidana will also miss out, after the defender limped out of Sunday's Superclasico with a sprained ankle. Tigre enganche Diego Morales takes his place in the 19-man squad.
The Albiceleste will take on their South American neighbours on May 25 at 16:00 (20:00 BST), in the newly opened Estadio Club Atletico Sarmiento in the northern province of Chaco.
Revised Argentina squad to take on Paraguay:
Goalkeepers: Juan Pablo Carrizo (River Plate), Adrian Gabbarini (Independiente).
Defenders: Luciano Monzon (Boca Juniors), Ivan Pillud (Racing Club), Federico Fernandez (Estudiantes de La Plata), Lisandro Lopez (Arsenal), Ismael Quilez (Colon de Santa Fe), Ariel Rojas (Godoy Cruz de Mendoza), Julian Velazquez (Independiente).
Midfielders: Cristian Chavez (Boca), Fabian Rinaudo (Gimnasia y Esgrima La Plata), Enzo Perez (Estudiantes), Diego Valeri (Lanus), Diego Morales (Tigre), Erik Lamela (River Plate).
Forwards: Lucas Viatri, Pablo Mouche (Boca), Gabriel Hauche (Racing), Mauricio Sperdutti (Newell's Old Boys).