Messi has scored 34 goals in 31 La Liga matches this season and eight goals in as many Champions League games, leaving Blanc in little doubt about the threat the forward poses.
"I think Messi is one of the best players in the world," Blanc said during a press conference. "He's unstoppable when he can get up speed and heads off on a dribble.
"Man-marking him would be the best thing for him and the best way for us to have a player sent off. You have to deal with the Messi problem collectively. We'll have to play very compact, and be aggressive."
Blanc also pointed out that his side can take confidence from the fact that they triumphed over Barcelona 3-2 in September last year.
"It's a match which is part of our analysis of Barcelona's team," he said. "We have a lot of others, such as the one against Sevilla, but it's going to enable us to show our team what to do and what not to do.
"There are some good lessons to be learned, firstly because we won, and that we're one of the only European teams to have scored three goals against Barca. Yes, it is a match we, the staff, have been focussing on in our preparation. The two teams played well. We'll have to repeat that display."
However, PSG have been dealt a blow as they will be without Zlatan Ibrahimovic, Marco Verratti and Serge Aurier. It is also unknown whether defender David Luiz will play since he is recovering from an injury.