"This could be the greatest semi-final in the history of the Champions League," said Puyol, who is suspended for the first-leg. "Two sets of fantastic players will be set against each other.
"They have very good players and really I expect it to be a beautiful semi-final. I am confident we will go through."
But he insisted that Barca have their own genius in Argie wonderkid Lionel Messi - who will be back to face the Red Devils after a long absence with a thigh problem.
He added: "Cristiano Ronaldo is a spectacular player. Not only with his game but he's also scoring a lot of goals.
"He's a player who can win a game on his own. But, as I said, we also have excellent players and now we are going to have Messi back who is a fundamental player for us."