The Geordie also feels United's midfield options are their strength.
Waddle told the Manchester Evening News: "Giggsy hasn't been used as much this season because of injury but he can still add something to the wing package. As a unit United are well blessed.
"Not only do they have a variety of wing skills but I can see them all contributing goals as well. I'd expect Nani to get 20 in a season now. Ashley Young can get about a dozen, Valencia can chip in with six and Ryan can get a few as well.
"United have one of the most varied and strongest wing packages available. Barcelona, for instance, have Messi pulling the strings but he is more central. David Villa is a striker who has been pushed wide.
"With the ball at their feet Barca don't have anyone better wide than Nani and Young. Take Messi out of their side and you don't have the players who can take men on.
"Clever wide men who can dribble and create are at a premium these days and United have them."