Alejandro Sabella’s men currently top the Conmebol group, but the Barcelona man believes they need at least two more wins before they can count themselves as part of the field for next summer's tournament.
"Mathematically, we will not be qualified with the six points, but it would be very difficult for it to escape from us,” he told reporters on Tuesday.
"We would be three quarters [through] the passage [to the World Cup]. We must get there but it will not be easy. Winning and accumulating points always makes everything a little bit better.
"Beyond that, the group is competitive, there are good teams. I do not like the atmosphere of optimism and euphoria very much. I prefer a different atmosphere because that is what makes you keep your attention."
Argentina host in-form Venezuela on Friday, and Pablo Zabaleta is anticipating a tough clash.
"Venezuela are a great team, and it will not be easy," he added.