Ferguson held a press conference earlier today, where he confirmed that the England striker will not be signing a new contract with the Old Trafford side.
Out-of-form Rooney has been the centre of a media circus ever since allegations regarding his private life were made public in early September.
The 24 year-old has suffered from a loss of form as of late, however, his intentions to leave the Manchester club has come as a shock to United fans.
In an interview with the club’s official television station MUTV, Ferguson revealed that Rooney had made his decision months ago.
“David (Gill) in the early part of the summer had opened talks with his agent and that was to be completed – or continued – after the World Cup. I was in the office on August 14 and David phoned me to say he wasn’t signing a contract. He came across to see me and said ‘I can’t believe this’. I could not believe it. I was dumbfounded.”
“Only months before he was saying this was the greatest club in the world and he wanted to stay for life.”
“We just don’t know what’s changed the boy’s mind really.”
Ferguson also confirmed that Rooney will miss United’s Champions League clash against Bursaspor on Wednesday night after the player was stretchered off during training with an ankle injury.