The former Liverpool man will be key if the Albiceleste are to shine in Brazil, but he has said that the familiarity of playing together for a number of years gives Spain a definite advantage.
He told Radio 9 de Argentina: "There isn't time to play in a similar way to Barcelona, this takes many years of work. We also can't pretend we are going to play like Spain because we are not going to achieve this.
"Spain without doubt are the best team in the world and it will be difficult to move them because they have a winning mentality."
The 28-year-old also spoke of his changing role at Barca, where he plays mainly as a centre-back rather than a holding midfielder, and his belief that his compatriot Marcelo Bielsa could eventually end up there as manager.
"Today in Barcelona I want to continue playing as a central defender, it is where I feel more comfortable and capable of performing," he said.
"I played all year as a defender but I am not going to regret that when the time comes to play as a number five for Argentina. (Argentina manager) Alejandro Sabella prefers that I occupy this position.
"(Pep) Guardiola has been a coach that has left a big impact on my career. He has a lot of similarities to Bielsa and obviously Marcelo is capable of managing Barcelona."