Sir Alex Ferguson has accused David Moyes of needing to prove his “manhood” by sacking Mike Phelan when Moyes took over as Manchester United manager two years ago.

Moyes took the job in summer 2013 and removed all of the coaching staff including Phelan, who had been Ferguson’s assistant manager. Yet in his new book, Leading, co-authored by Michael Moritz, Ferguson claims this showed weakness from Moyes, whose tenure lasted only 34 Premier League games.

“I’m sure there are things that David would do differently if he had the opportunity to relive his time at Old Trafford,” Ferguson writes. “Such as keeping Mick Phelan who would have been the invaluable guide to the many layers of the club that Ryan Giggs is to Louis van Gaal today.

“There is no point suddenly changing routines that players are comfortable with. It is counterproductive, saps morale and immediately provokes players to question the new man’s motives. A leader who arrives in a new setting, or inherits a big role, needs to curb the impulse to display his manhood.”

Ferguson also confirms that Pep Guardiola rejected the chance to succeed him by refusing the Scot’s request to call him before accepting a job at another club. The revelation confirms that Moyes was not the first choice to replace him.

After leaving a supremely successful tenure as Barcelona coach in 2012 Guardiola was a free agent. Guardiola’s decision to become the Bayern Munich No1 before the 2012-13 season came soon after Ferguson had dined with the Spaniard in New York.

“I had dinner with Pep Guardiola in New York in 2012, but couldn’t make him any direct proposal because retirement was not on my agenda at that point,” Ferguson said. “He had already won an enviable number of trophies with Barcelona – and I admired him greatly. I asked Pep to phone me before he accepted an offer from another club, but he didn’t and wound up joining Bayern Munich in July 2013.”

In February 2013 Ferguson informed the Glazer family, who own United, that he would be retiring. The timing meant other potential candidates, who included Jürgen Klopp, Carlo Ancelotti and Louis van Gaal, who eventually replaced Moyes, were ruled out.

“Life is such that the best of theories, or the best of intentions, sometimes don’t translate into practice,” Ferguson said. “Believe me, the United board wanted nothing more than to select a manager who would be with the club for a long time. When we started the process of looking for my replacement, we established that several very desirable candidates were unavailable. It became apparent that José Mourinho had given his word to Roman Abramovich that he would return to Chelsea, and that Carlo Ancelotti would succeed him at Real Madrid.

“We also knew that Jürgen Klopp was happy at Borussia Dortmund and would be signing a new contract. Meantime, Louis van Gaal had undertaken to lead the Dutch attempt to win the 2014 World Cup.”

Ferguson also claims that Mino Raiola, the agent of Paul Pogba, prompted the French midfielder’s departure from United to Juventus. “There are one or two football agents I simply do not like,” Ferguson said. “And Mino Raiola, Paul Pogba’s agent, is one of them. I distrusted him from the moment I met him. He became Zlatan Ibrahimovic’s agent while he was playing for Ajax, and eventually he would end up representing Pogba, who was only 18 years old at the time.

“We had Paul under a three-year contract, and it had a one-year renewal option which we were eager to sign. But Raiola suddenly appeared on the scene and our first meeting was a fiasco. He and I were like oil and water. From then on, our goose was cooked because Raiola had been able to ingratiate himself with Paul and his family and the player signed with Juventus.”

Leading, by Alex Ferguson with Michael Moritz (Hodder & Stoughton, £25)