"What we're seeing with Rio now is a maturity in terms of helping other people round about him and being a leader in that respect," Fergie told Sky Sports News.
"He's never lost that technical advantage he has over other defenders.
"The ability and balance to take the ball out of defence has always been there."
The United boss also heaped praise on Ronaldo and believes that at just 23- years-old the winger will improve as he gets older.
"For a winger to score 42 goals, that in itself deserves recognition," said Fergie.
"His performances apart from that were exciting. He's a player who always wants to take the ball and always plays with such great courage.
"Where he will improve is his authority, his timing.
"Experience gives you better timing, better authority and better decision making and handling all situations, that's what maturity does.
"In the case of Cristiano, at 23, we expect that to progress the right way.
"When you look at the quality of the players involved it is a measure of the success of the team last season.
"It was a marvellous year for us and, quite rightly, we've been recognised in a big way."