Argentina coach Diego Maradona played in four World Cups from 1982 to 1994, winning the trophy in 1986 and reaching the final in 1990 — both times against Germany — and his experience is rubbing off on the squad.
Pastore said Maradona had "gone through every experience" and "knows what to say" when players have doubts or questions.
Germany has won its last two matches against Argentina at the tournament: a 1-0 victory in the 1990 final and a penalty shootout win four years ago in the quarterfinals.
Argentina's only win over Germany in the World Cup was the '86 final, when Maradona inspired his side to a 3-2 triumph. Maradona also oversaw a 1-0 victory in the teams' last meeting, a friendly at Munich in March.
Pastore said "of course" Maradona speaks about the 1986 win, but "he doesn't just talk about that World Cup, but the four World Cups he's played in."
"Diego has gone through every experience possible in football and that helps us a lot. If you've got a doubt about something or a question, he knows what to say."
Pastore, who plays for Italian club Palermo, has made two substitute appearances for Argentina so far, coming on against Greece in the group stage and against Mexico in the second round.
The forward has impressed with his ability to retain possession in those cameos and has an outside chance of forcing his way into the starting lineup against Germany.
His ability to link with Messi is also in his favor.
"When you are playing with Leo, football is made to look easy," Pastore said. "I think every player that lines up alongside him knows that you can give him a pass and he will always give you a perfect pass in return. That's very important to us."
Maradona refereed an 11-a-side game on one half of the field Wednesday at Argentina's base at the University of Pretoria.
He barked out encouragement to his players and awarded two penalties, one converted by Messi and the other by Carlos Tevez.
The session ended with the majority of the players laughing and shooting balls from the edge of the box at teammates and staff who had made mistakes during the practice.
Argentina has no injury concerns or suspensions ahead of Saturday's match in Cape Town.