“He has been pretty immature since he came to the club, but you are seeing the development now,” Ferguson told MUTV.
The former Sporting Lisbon starlet has struggled to establish himself at Old Trafford since arriving in July 2007, and finally made his 50th league appearances for the club in last weekend's 3-1 victory against Arsenal at the Emirates Stadium.
“The manager has shown confidence in me, I have been given more time on the pitch and that has given me belief in myself," he said in the Mirror.
"I know I can do a good job for the team, we believe in ourselves and that we can win titles and have success this season."
Nani’s new-found form has given Ferguson a selection dilemma for the rest of the season with Antonio Valencia also vying for first-team action.
"We are all delighted with [Nani]. We are getting consistency from him now," Ferguson said.
"It gives me a massive decision to make between Nani and Valencia."
