Sir Alex Ferguson believes Cristiano Ronaldo has become the 'complete player' since joining Real Madrid from Manchester United in 2009.
Ronaldo, 27, was once again edged out of Ballon D'Or honours by Barcelona's Lionel Messi, but Ferguson says the Portuguese winger has improved significantly during his time in La Liga.
After watching his former player in action against Manchester City last month, the United boss claims Ronaldo's impressive form during his time at Old Trafford has never waned.
"Maturity brings many things," Ferguson told Inside United. "When I went to see them play against City, some of his decision-making in terms of passing was brilliant. One-touch passing, good crosses.
"In the six years we had him, you just saw his game grow all the time, and he was a fantastic player. Now you see the complete player.
"His decision-making, his maturity, his experience, plus all the great skills he has got, they all make him the complete player."
Ferguson has begun preparations to stop Ronaldo's attacking prowess ahead of United's clash with Real in the Champions League knockout stages next month.
"Obviously you hope that when you draw Real Madrid it's in the final," he said. "It will be a big, big event - we're the two most high-profile clubs in the world and I think they will be great games."