He told MUTV: "I always had big, big, big respect (for United). That's why I remember my time with Porto here as one of the most important for me, because we beat such an amazing club - and that's why I'm so excited to play with Inter Milan against Man Utd.
"When I said 'I want Man Utd', some people maybe thought 'this guy is crazy' - because he wants the top team - but I want it because they are the top, because it's difficult and because it's special and for my team and my players, it's a different thing.
"I won't need to motivate people because they are already motivated. The best (competitions) match players against the best - and the best at the moment is here.
"We can win it. We know Man Utd is a special team with special players. You look at how solid they are in defence and how dangerous they are in attack. You look to the dug-out and you see the talent is there; I look behind me, and even Nani is behind me.
"But Inter is a clever team, an intelligent team, a team with a lot of experience. We have some talent and we know how to play the game, so I think it will be a close match."