Sir Alex Ferguson believes Cristiano Ronaldo has turned into "the complete player" since his departure from Manchester United in 2009.
Ronaldo has once again been overlooked for the Ballon D'Or in favour of Lionel Messi, who has now collected the prestigious award on four consecutive occasions.
However, the Portugal superstar, who won it in 2008 in recognition of his phenomenal 42-goal contribution to United's Champions League and Premier League double, remains Messi's closest challenger.
And, for the first time since he brought Ronaldo to Old Trafford, Ferguson will have to find a way of stopping the 27-year-old next month given Real Madrid lie in wait in the Champions League.
It will not be an easy task.
Ferguson spoke to his protege in Manchester ahead of City's encounter with Real in November, then went to the Etihad Stadium to see the winger take the Blues apart in the opening stages of what ended up being a 1-1 draw.
And the Scot has no doubt the improvement he oversaw during Ronaldo's six-year stint at United has continued since his arrival in Spain.
"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 is trying not to think about the best way to combat Ronaldo, preferring instead to concentrate on the players in his own squad and exactly who will be fit for the first leg at the Bernabeu on February 13.
"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."
Before that, United have a few interesting Premier League assignments, none more so than the visit of Liverpool to Old Trafford on Sunday.
The corresponding fixture last term marked the low point in the row that followed Luis Suarez's racist slur of Patrice Evra at Anfield the previous October.
Having informed manager Kenny Dalglish he would shake Evra's hand, the Uruguayan then refused, triggering a furious reaction from the Frenchman and subsequent apology from Suarez.
Evra then shook hands with Suarez at Anfield this season, leading Ferguson to conclude the action will be confined to the actual match this weekend.
"There will always be a certain build-up to a Manchester United-Liverpool game, simply because of the history between the two clubs, the two most successful in the country," he said.
"It brings its own agenda in terms of profile and pre-match discussion.
"Last year it was unfortunate with the Suarez behaviour. I think hopefully it is behind both clubs now and we can just look forward to the game."