Manchester United know a clean sheet will put them in the last eight of the Champions League following a 1-1 draw in the Bernabeu last month.
Real have twice beaten Barcelona since that first leg - once with a ruthless counter-attacking performance in Catalonia - but captain Vidic reckons United can avoid the same fate.
He told The Sun: "When Real play against teams who drop deep they can have a bit of trouble, because they aren't a team that crosses the ball a lot.
"If you get players behind the ball it is difficult for them to get through and they have to shoot from distance because they don't have many crosses.
"They don't have many alternatives. They have Cristiano Ronaldo, who can jump when he is in the box, but he is the only one. I don't think the other players are good in the air."
It was a Ronaldo header which earned Real a draw three weeks ago and Vidic, not guaranteed to start at Old Trafford, is not about to underestimate the threat of a former team-mate he rates as among the world's best.
He said: "Ronaldo can shoot with his left, his right, he can jump and head the ball. He can dribble, he can do everything.
"I have played with him and trained with him and I know how many sacrifices he has made to be where he is. He worked so hard on everything and people forget that."
And Vidic is not ruling out a reunion with the Portugal star, who plays at his former home for the first time since his 2009 departure.
He said: "Ronaldo is a United supporter and still follows United, he still misses the club and the environment here, so I wouldn't be surprised to see him come back.
"It would be a big ask for many reasons, but I would love to see him here. I don't know what atmosphere he has at Madrid, so I can't really talk about that, but all I can say is that I enjoyed playing with him, he enjoyed it here and it will be great to see him."