The Albiceleste coach tried two tactics in the first session since Saturday's 4-0 win over Ecuador, one of which saw the ex-captain drop back to form a five-man backline
'El Jefecito' has been a regular at centre-back since moving from Liverpool to Catalunya in 2010, but for the Seleccion he has remained in his more natural position in the midfield under Sergio Batista and now Alejandro Sabella.
The former Estudiantes coach, however, gave some indication that he was considering the ex-River player in a more defensive role as the Argentine side trained on Tuesday morning in their Ezeiza home.
Mascherano started the session in his habitual role, but when Sabella moved his players around to try a 5-3-2 scheme he went further down the pitch to play alongside Ezequiel Garay and Federico Fernandez.
While the trainer has still not confirmed his chosen starters to face the 2014 World Cup hosts, it appears certain that the attacking trident of Lionel Messi, Gonzalo Higuain and Sergio Aguero will be broken up in favour of a two-man forward line.
Messi played both parts of the session, accompanied first by Higuain in a 4-4-2 followed by El Kun when the switch to five at the back was played.
The choice of formation would seem to be the deciding factor when it comes to picking the final squad. Atletico Madrid's Eduardo Salvio is one player who could benefit from the changes, as he appeared on the left of an attacking triumvirate during practice.
The first-team XIs that took part in the first and second halves of training were as follows:
(4-4-2): Orion; Zabaleta, Garay, Fernandez, Clemente; Sosa, Gago, Mascherano, Di Maria; Messi, Higuain.
(5-3-2): Orion; Zabaleta, Garay, Mascherano, Fernandez, Clemente; Di Maria, Gago, Salvio; Messi, Aguero.