Nani's journey to Old Trafford has taken place a year ahead of schedule, with Ferguson forced to move quickly for the Portugal Under-21 star who, like Cristiano Ronaldo, developed a big reputation at Sporting Lisbon.
"We have been monitoring Nani for almost as long as Cristiano," said Ferguson.
"In a perfect world, he would have stayed in Portugal for another year but circumstances forced us into action.
"He is different to Cristiano in that he can play on both sides of the pitch but also in the middle. He is quick, has a terrific engine and I know we are getting a very talented, flexible player."