The 28-year-old has little doubt that the reigning Spanish champions will emerge victorious from their Champions League tie, and is excited about his return to Old Trafford
The Portugal international, who represented the Red Devils between 2003 and 2009, has stressed that the Premier League leaders will pose a stern test, but has insisted that his side are superior.
"I believe things will go well. In my opinion Real Madrid have a better team, but we have to show that on the pitch because United are a very united team and always have been in recent years," the attacker told Uefa's official Champions League magazine.
"They're a team that always do well, every year they're at the top and therefore a team we respect a lot. It will be an extremely difficult match, especially in Manchester.
"The game at Old Trafford will be a match in which I will feel a lot. I was there for six years. I have a lot of friends there, people I will see with great pleasure, it will be a match with a lot of emotions."
The first leg is scheduled to take place at the Santiago Bernabeu on February 13.