The Dutchman has netted 15 times in 22 games since joining in the summer and has created a host of goals for others. A number of his strikes have also turned out to be vital winners, the most notable coming earlier this month in the Manchester derby.
Sir Alex has nothing but praise for 29-year-old who, the boss believes, has stood out above the rest so far this season.
"I reckon here at Manchester United we got our Christmas present early – right at the start of the season in fact, when Robin van Persie arrived at Old Trafford," writes the manager in his column for Wednesday's United Review.
"I am reluctant to subscribe to the cult of an individual because I firmly believe that the essence of a successful football team depends on team-work, and neither are we a one-man team, but sometimes there really is a situation where you are lucky enough to find the last piece of the jigsaw.
"We did it when we brought Eric Cantona to Old Trafford where he proved to be the right player at the right club at the right time. He became the catalyst and springboard for our surge to success. It doesn’t have to be signing someone for a record fee; Eric was in fact a snip at a million. Cristiano Ronaldo was not a record buy either but he certainly made a difference as he prospered with us to the extent that he came to be regarded by a lot of people as the world’s best player.
"We didn’t pay a ransom for van Persie either, but as I take stock as we approach the