The clues were there, pretty much from the start, that David Moyes' biggest battle as Manchester United manager would be to convince himself that he was the man for the job.

Initially, the players, supporters and Old Trafford hierarchy were happy to buy into the bright new era and give Sir Alex Ferguson's successor -- the supposed "Chosen One" -- the time and backing to deliver a seamless transition and continuation of the glory days which became the norm under his predecessor. But less than a week into United's 2013 preseason tour of the Far East and Australia, Moyes let slip his inner doubts during a speaking engagement at Sydney's Westin Hotel.

"I tell you, there's not one person who would turn around and say: 'Taking over Manchester United, you think you can walk in there and breeze in and think you can do it easily?'" Moyes said. "Of course not. There has to be an element of fear that comes with managing a club like Manchester United.

"You would have doubt if anybody took over this job, but in my own way, I've got to say I feel it's the right job for me at the right time and hopefully I'll make it work."

In one statement, Moyes exposed the fault lines which would ultimately cost him his job less than 12 months later -- the self-doubt and fear which transformed United from the best team in the country into a group of players incapable of even qualifying for the Europa League.

Much water has passed under the bridge since Moyes was dismissed by United in April 2014, two days after a humiliating 2-0 defeat at Everton with a fancy dress version of the Grim Reaper mocking the Scot as he saw his team, and career, falling apart in front of him at Goodison Park. But as he prepares to walk down the Old Trafford touchline as Sunderland manager on Boxing Day for the first time since leaving United, the passage of time allows for truer perspective of his disastrous spell in charge and why it went so badly wrong.

Moyes has insisted in the years since his departure that he was given neither the time, money nor patience afforded to his successors -- a claim dismissed by the United hierarchy -- but there can be no doubt that following Ferguson has been a challenge that neither Moyes, Louis van Gaal nor even Jose Mourinho has yet been able to rise to successfully. Moyes' failure was down to more than ending the tradition of low-fat chips on the night before games or taking fish fingers off the menu at the Aon Training Complex because his players should not be eating "kids' food," but those tweaks to a previously slick machine certainly eroded the confidence and trust of his players.

On the first leg of his only summer tour, when United lost to a local team in Bangkok, senior players were surprised by Moyes' downbeat reaction to a result in a game purely designed for boosting fitness levels after the summer break.

There were further instances of eyebrows being raised by an approach deemed tailored more for Everton than a club of United's stature, both in the dressing room and boardroom, with the club prepared to spend big on Thiago Alcantara and Cesc Fabregas, only for Moyes to insist he did not know enough about Barcelona youngster Alcantara to sign the deal off before allowing the unsuccessful Fabregas pursuit to waste valuable time during a summer window which eventually saw just one player -- Marouane Fellaini -- arrive in the minutes before the transfer deadline.

Sources tell ESPN FC that executive vice chairman Ed Woodward was desperate to prove his backing by making several signings, but Moyes was too cautious in his approach to transfers. Jamie McDonald/Getty Images

United maintain that substantial funds, equal to those spent by Van Gaal and Mourinho, were at Moyes' disposal -- senior United sources have told ESPN FC that executive vice chairman Ed Woodward was desperate to prove his backing by making several signings -- but Moyes was too cautious in his approach, prompting the "Dithering Dave" nickname of his Everton days to resurface within Old Trafford.

On the pitch, tactics began to confuse players, with Moyes sometimes changing formations and team selections on the day of a game, while his negative assessment of the team's prospects as results began to fall away unsettled many connected to the club. Talking of "aspiring" to be like Manchester City and claiming Liverpool were "favourites" to win at Old Trafford infuriated players and supporters alike, but while Moyes is a genuinely honest and engaging man, his inclination to focus on the negatives became a debilitating flaw during his time at United.

Players began to mutter about the chaos behind the scenes, with established stars bemused by the manager's safety-first approach. Meanwhile, the trajectory of results set alarm bells ringing for Woodward and United's owners, the Glazer family.

Positives were in short supply for Moyes, who has since admitted that he would have treated the job differently had he realised that his six-year contract would count for nothing if he failed to get it right straightaway. Yet a six-year deal did count for nothing just 10 months later, when Moyes was sacked with United languishing outside the European qualification positions in seventh.

Hindsight is a wonderful thing and nobody will ever know whether United's post-Ferguson nightmare would have been avoided had the club been able to replace their legendary manager in 2013 with Mourinho, Pep Guardiola, Carlo Ancelotti, Jurgen Klopp or a similarly stellar name from the coaching world. Moyes was the wrong man at the wrong time, lacking both the track record and personality to take the job on -- a reality he hinted at, perhaps unknowingly, that day in Sydney.

There are some who believe that Moyes' tenure set United back years, with his brief spell in charge eroding the previously high levels of confidence and certainty and leaving both Van Gaal and Mourinho to inherit an institution with its self-belief shaken to the core. The Chosen One was, without doubt, the Wrong One, and he may approach his return on Monday with some trepidation.

Moyes can be assured of a respectful welcome by United and the club's supporters, however. There will be no jeering or abuse from the stands for a decent man who was unable to meet the challenge laid out before him.

But the scars of his 10-month reign have not healed for either Moyes or United, and there is still some distance to travel for both before the 2013-14 season becomes a footnote in their shared histories.