Granero is also a fan and knows how desperate the club are to claim their 10th European Cup.
He told the London Evening Standard: "I don't think they will be intimidated playing at Old Trafford. I have played in both stadiums and the Bernabeu is the most intimidating stadium I have ever played in - for the other teams and the players in the home team, too!
"Real are technically behind so they have to score, they will press high the same way they did in the first leg. I think Manchester United will wait for the counter-attack.
"In this kind of game with these big teams and big players, anything can happen but if I have to bet my money, I would have to bet on Real.
"I know this squad and players and they always play their best level in these massive games. Matches like this bring out the best in them.
"To me the most important player at Real is Xabi Alonso. Around him everything works. If he is in the game, everything works properly, then Real have so many players who can win the game, like Cristiano."