The 1998 World Cup winner feels the Ligue 1 powerhouse stand little chance against the Primera Division leaders
The Blaugrana are one of the favourites to win the competition, and Petit has little doubt that his former team will reach the semi-finals at the expense of PSG.
"On the pitch, Barcelona are unbeatable," Petit was quoted as saying by RMC Sport.
"Do Paris Saint-Germain have the ability to sit deep and defend as a block, like Inter, AC Milan and Chelsea have done over the years? Will we see Zlatan Ibrahimovic fight for the ball near his own corner flag like [Didier] Drogba?
"I do not think so. Barcelona might no longer have the same vibe from before, but they are all champions who step up when it matters most. Just look at what they did against Milan."
Tuesday's encounter at the Parc des Princes is scheduled to kick off at 20:45CET.