A series of injuries have limited the Portuguese international to just 17 appearances in all competitions this year.
However, with United battling for honours in both the Premier League and FA Cup, the 26-year-old has insisted that he is ready to contribute over the coming weeks.
"Now my confidence is high and I think the best is still to come from me. This is my time and I think I can be important for the team in these big games. Because I was injured for two months, it means I'm fresh now when some other players are starting to get tired," he told the club's official website.
"I feel I'm in good form and I've nearly arrived at my peak. I think over the next few games I can surprise a few people.
"I want to show the manager that he can trust me and he can believe in me in every match. I want to show him my contribution can help win games. So I'll keep working hard to make sure I'm ready to respond every time I get a chance."
Nani joined United from Sporting Lisbon in the summer of 2007.