The Argentine praised his compatriot for being the best player in the world, and insists les Parisiens can make it into the semifinals despite the Blaugrana's quality.
Les Parisiens will be hoping to emulate AC Milan's home win against the Blaugrana but avoid the subsequent collapse at Camp Nou when the two European giants clash in their Champions League quarterfinal in April.
"He's the best player in the world!" Pastore responded when asked about Messi by PSG's official website. "He shows it match after match. For us Argentines, he is a reference and an example. I am delighted to be playing against him, it will be a very special moment for me. There will be a little emotion there for me.
"We will have to remain focused [against Barca] for 90 minutes. You have to stay calm when they have the ball. Barcelona are a team that exploit the smallest error from the opposition to score. From that moment, it is very hard to come back."
PSG is naturally the underdog against the 2010-11 Champions League victors, but Pastore is confident that a semifinal berth is not beyond the squad.
"At this level of the competition, every team is strong, but anything is possible," he added. "We need to play two great matches of football.
"If we stay focused we will have reason to hope we'll go through. It's the only way of getting through this round."