* Beckham thought he was bigger than United
* Keane rage, frightening to watch
* Ronaldo was our wizard
David Beckham thought he was too big for Manchester United and later surrendered part of his career by moving to the United States to play for LA Galaxy, former manager Alex Ferguson said in his autobiography published on Tuesday.
Beckham, who burst into the limelight after coming through the ranks at United, features heavily in "My Autobiography", published by Hodder and Stoughton, Ferguson's recollections of the years since the 1999 treble-winning season.
Ferguson's relationships with former skipper Roy Keane, current striker Wayne Rooney and arch-managerial rivals such as Rafa Benitez and Arsene Wenger also get plenty of wordage.
Ferguson, 71, ended 27 years in charge of one of the world's biggest football clubs last season having claimed a 13th Premier League title for the club.
During a time of huge change in the football landscape, the one constant to emerge was Ferguson's vice-like grip on authority in the face of the big egos and even bigger salaries of those under his command.
He was regularly challenged but invariably emerged on top.
Beckham is a prime example, his relationship with Ferguson damaged irrecoverably after an FA Cup defeat by Arsenal in 2003 after which Ferguson kicked a boot at Beckham after he was "dismissive of my criticism".
Ferguson said instead of "becoming a United legend" Beckham allowed his love of celebrity get in the way.
"David was the only player I managed who chose to be famous, who made it his mission to be known outside the game," Ferguson wrote in a chapter devoted to Beckham. "I felt uncomfortable with the celebrity aspect of his life."
After the "boot" incident which left Beckham with a cut forehead, Ferguson told the United board "he had to go."
"The minute a Manchester United player thought he was bigger than the manager he had to go," Ferguson said. "David thought he was bigger than Alex Ferguson. It doesn't matter whether it's Alex Ferguson or Pete the Plumber. The authority is what counts.
"You cannot have a player taking over the dressing room. That was the death knell for him."
Beckham, who won six league titles with United, was sold to Real Madrid soon afterwards and eventually joined LA Galaxy in 2007 - a move that baffled Ferguson.
"There was no footballing reason for him to go to America," Ferguson said. "He started making decisions that rendered it hard for him to develop into a really great footballer.
"I would look at him and think, "What are you doing son?"
Ferguson also saw off former skipper Keane after the tempestuous Irishman lambasted his team mates on the club's TV channel in 2005.
"The hardest past of Roy's body is his tongue," Ferguson wrote. "What I noticed that day as I was arguing with him was his eyes narrowed to black beads.
"It was frightening to watch. And I'm from Glasgow.
"What you did in that video was a disgrace," Ferguson recalls of his reaction to Keane's outburst.
Wayne Rooney came close to leaving in 2010 when he said he would not sign a new contract because the club did not share his ambition and his relationship with Ferguson was again strained in the Scot's final season.
"Wayne said we should have pursued Mesut Ozil who had joined Real Madrid from Werder Bremen. My reply was that it was none of his business. I told him it was his job to play and perform.
"It was a sorry episode for Wayne because it portrayed him as a money man. With the fans, it left a residue of mistrust."
Ferguson, who said he twice turned down the England job, criticised the FA's decision to allow Rooney a week's holiday before Euro 2012 because he was banned for the first two games.
"It was not wise," he said. "If he missed a couple of games for United it could take him four or five to get his sharpness back. He would receive no leniency from me."
While Ferguson says Rooney "has a gift for producing great moments" his highest praise is reserved for Cristiano Ronaldo, the man bought to replace Beckham and who he said gave him a "surge of excitement" when he first saw him play in Lisbon.
"Cristiano was the most gifted player I managed," wrote Ferguson. "He surpassed all the other great ones I coached at United - and I had many."
"We lost our wizard to Real Madrid in the end," added Ferguson, who resisted the Spanish club's bid to sign him in 2008. "I know you want to go to Real Madrid (Ferguson told Ronaldo in 2008), but I would rather shoot you than sell you to that guy now (Real president Ramon Calderon) now."
While Ferguson's sometimes strained relationship with Wenger turned into one of mutual respect, the same could not be said of his dealings with former Liverpool manager Benitez.
Ferguson said the Spaniard had no interest in forming a relationship, branding him a "silly man".
"Once you made it personal, you had no chance, because I could wait. I had success on my side," Ferguson said.
There is little room for regret in Ferguson's book, although losing the title in the dying seconds of the 2011-12 season to Manchester City still hurts.
"Of all the setbacks I endured, nothing compared to losing the league to City," he said, although regaining it last year proved sweet revenge.
"My final thought on City was that they couldn't call on enough players who understood the significance of what they had achieved by winning the first title for 44 years."