Rooney was the subject of bids from Chelsea after it became apparent he was willing to leave Old Trafford and the striker, speaking ahead of England’s World Cup qualifier against Montenegro on Friday, has explained the cause of his discontent.
According to Rooney, Ferguson’s decision to use him in midfield occasionally following the signing of Robin van Persie forced him to consider a future away from United.
"Everyone at the club knew where I wanted to play and I think that's why I was disappointed,” Rooney said. “I got told to play in midfield and I didn't want to. I just think there had to come a point when, for my own career, I had to be a bit selfish really.
"I actually felt when I played in midfield I did okay, but I didn't want to play there. I've had no problem in the past playing out of position. But I felt I deserved the right to play in my position and that wasn't happening."
At the time, Rooney never complained publicly about his changing role under Alex Ferguson - and he even went wrote on Twitter a year ago that he was "really enjoying my new midfield role".
Twitter users are now re-tweeting Rooney's words from last October and accusing him of changing his tune, though he clearly would have been very ill-advised to have publicly criticised his then-manager like Alex Ferguson.
Rooney also blamed his poor form last season on his unhappiness at the change of position.
"I think, naturally, I was a bit disappointed and maybe that affected some of the games I played. I know myself that last year wasn't my best season but there were times when I was playing in different positions," he added.
"I didn't feel I got a consistent run of games up front. Sometimes when you're not playing in one position all the time it's difficult to adapt."
As for whether Rooney is now content to stay at United for the long term, the striker stopped short of committing his future to the club – even if he did say that, with five goals in his past six games, he is enjoying playing under David Moyes.
“Obviously there’s been a lot of stuff happening and people waiting for me to say whatever but I’ve spoken to the people who matter at the club and we’ve known ourselves what we’re doing," Rooney said.
“I’m not going to go around saying: 'I wanted to stay or I wanted to leave.’ I’ve just got my head down and worked hard. I’ve been focused and been wanting to prove to people that I’m a top player. I wanted to prove it to myself really rather than anyone else.
"You can see I'm playing and I'm happy in my football," he added. "I'll have more discussions with the club and we'll see what happens from there.
"David Moyes has come in, he's playing me up front and I'm enjoying it. I'm not saying I wouldn't [go into midfield] for instance if it was the last 10 to 15 minutes of a game, if we were holding on a bit and I got asked to drop to the left, or drop back, to help see out the game.
"I'd always go in and try to help the team. I'm not saying I'd throw my arms up and not do it. I can play in midfield. Maybe when I'm a bit older, losing my legs a bit, I can go back there."
The goals for a leaner, fitter Rooney have flowed since Moyes implemented a tough training regime, and it is that work at Carrington that the player credits for his sharpness.
“Honestly the training has been so hard,” he said. “We’ve done a lot of different types of training – a lot more longer running, quicker running, sharper running. That’s really benefited me. I feel as fit as I ever have done.”