Nani made a scoring return to the United side at Old Trafford, coming off the bench to inspire the Red Devils to a 2-1 victory over the Royals and keep their treble chase alive.
Ferguson has admitted that the Portuguese winger will give him a selection headache if he can produce displays of the same quality on a regular basis.
He told The Independent: "Nani is a fantastic talent. He has got great talent, we know about that.
"I had a feeling he would win the game for us. You could see he was right on form when he came on. He had two great strikes immediately and he was a threat to them after that all night.
"It is a good addition. If he keeps that form it makes my job more difficult."
United are back in Premier League action this weekend against Queens Park Rangers at Loftus Road.