Van Persie only arrived at Old Trafford from Arsenal last summer but the boss has clearly made a big impression on the Dutchman.
“I am really sad to hear that the manager is retiring,” van Persie posted on his official Facebook account on Friday morning. “But I'm really happy I have had the opportunity and the honour to work with him.
“He is a great manager and, above all, an even greater person. I have to thank him for an amazing year and for making my dream come true by winning the league.
“I wish him and his family the very best.”
Sir Alex will lead United out twice more – against Swansea at Old Trafford on Sunday and then, seven days later, against West Bromwich Albion at The Hawthorns – before stepping down from a position he’s held since November 1986.
Current Everton manager David Moyes will take over on 1 July.