By FOX Sports Staff
The two sides have been drawn for the quater-finals of the competition with Barca the heavy favourites to secure a win in Parc des Princes on the night.
This is despite the fact that PSG, backed by rich Qatari owners, have assembled one of the best playing squads in the world with the likes of Zlatan Ibrahimovic, Thiago Silva, Pastore and Ezequiel Lavezzi just some of the names on the teamsheet.
They know that the La Liga side will rely heavily on the talents of star forward Messi, who recently secured the record of having become the first player to score consecutively against all teams within a division.
Pastore is intimately aware of Messi's ability as he has regularly featured alongside the former Newell's Old Boys youth graduate for the Argentina national team.
"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," Pastore confessed on the PSG official website.
"He's the best player in the world! He shows it match after match.
"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."
The 23-year-old midfielder also knows that few are tipping his side to progress to the next round but he's keeping his fingers crossed and hoping for the best.
"At this level of the competition, every team is strong, but anything is possible. 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."
The former Palermo player has been at the Ligue 1 club for two seasons and has made 80 appearances across all competitions thus far.