Nani tends to bridle these days when comparisons are made with the former world player of the year.
But Ferguson believes he is becoming a key man in his own right.
"Nani has always had potential," he said. "Some of those who come to our club from abroad do it quickly, others gradually grow into it. Nani is one of those.
"Even Cristiano took two or three years to get the maturity in his game.
"That is what we are seeing with Nani now. The goals have been fine but his assists are very high. He is progressing really well."