The Bulgarian striker, who arrived at Old Trafford for a club-record fee in September 2008, went on to net 56 times in 149 United appearances but found first-team opportunities increasingly limited in the past 12 months.
An artist as much as a sportsman, Berbatov delighted in making football beautiful. He took as much pleasure in setting up goals as he did scoring them, although he will probably be best remembered by United fans for a historic hat-trick against Liverpool – the first by a Red in 64 years – in 2010/11. That same season he finished joint top scorer in the Barclays Premier League.
The emergence of Javier Hernandez and Danny Welbeck impaired Berbatov's progress, however, and he made just half as many appearances (21) in 2012/12 as he did the previous term.
Speaking on Friday morning, Sir Alex told journalists that the striker fell foul to United's change in playing style.
"He's a very talented player and his contribution was good, particularly in home games," he said. "But when we changed our game, it didn't suit him. We started to play with more speed and teams were getting organised very quickly against us.
"Therefore, we had to change the way we wanted to play and it didn't suit Dimitar but he's a very talented player. Wherever he goes, he'll do well."