Alex Ferguson
Ferguson feels Manchester United was too big for David MoyesReuters

Former Manchester United boss Sir Alex Ferguson has finally admitted his mistake of naming David Moyes as his successor, saying that the Red Devils managerial job was too big for the ex-Everton manager.

Ferguson had handpicked Moyes to be his successor at Old Trafford following his retirement after the 2012/13 season, where he secured a final Premier League title for United.

However, the appointment proved to be a terrible mistake as Manchester United's form deteriorated under Moyes and they eventually finished seventh in the Premier League last season.

The Red Devils' poor form in the Premier League and other competitions eventually led to the inevitable sacking of Moyes, who was later replaced by Louis van Gaal.

Although Ferguson earlier refused to comment on Moyes short reign at United, the Scot has finally broken his silence, giving his views on why the former Everton boss failed at United.

"He hadn't realised just how big United is as a club," said Ferguson in his updated book "My Autobiography."

 The 72-year-old boss feels that the main reason behind United's slump in form last season was due to Moyes lowering the team's playing tempo.

"The reason for playing at speed was that United players had been accustomed to operating that way," he added.

"If the tempo slowed for any reason, I would be into them at half-time. 'This is not us,' I would say. Playing with speed never hindered our results. It was our way: energy and determination in the last third of the pitch."

Ferguson also feels that Moyes bringing in his own backroom staff instead of retaining the services of the existing coaches, contributed to United's downfall last season.

"Maybe David felt that at such a massive club he had to be sure that all corners were covered in terms of his support system. I felt that network was already there, with plenty of great people already in important slots."

However, Ferguson, who is now a director at Old Trafford, rejected suggestions of him being solely responsible for Moyes' appointment and sacking.

"There appears to be an accepted view out there that there was no process. Nonsense. We feel we did everything the right way: quietly, thoroughly, professionally."

Ferguson also dismissed accusations of him contributing to United's decline by leaving an ageing squad for his successor, pointing out that 11 of his Premier League title-winning squad in 2012-13 were at the age of 25 or less.

"Chelsea started the current season as favourites for the title, with a squad that also had six players in their 30s. I don't hear any grumbles about the age of their group," he added.

"Antiquated was a bizarre description of the structure I left behind at Manchester United. Have you seen our new training ground?"