Sir Alex Ferguson, probably the most legendary manager in soccer history, did not become legendary out of nothing. Twenty seven years running the biggest club on earth is perhaps not enough to secure such a status, but when you combine this kind of unprecedented longevity with winning the amount of trophies he did, then you are quite simply up there. However, one other thing contributed to make Ferguson a true great. I am referring to his famous ability to pick talent, to know when the time had come to say goodbye to an established star, and to make the right decision in those decisive either/or situations.

He identified Brøndby’s Peter Schmeichel as Old Trafford’s long-term keeper and even got him for a bargain. He got his hands on Eric Cantona, although the move was probably more coincidental than a result of will. He ruthlessly got rid of Andrei Kanchelskis, Paul Ince, and Mark Hughes in 1995 in order to make way for unknown and homegrown kids such as Paul Scholes, Gary Neville, and David Beckham. Before what turned out to be his final season in charge of Manchester United, Ferguson beat “the noisy neighbors” from City to the signature of Robin van Persie who then went on to become the famous difference between the two Manchester teams in his first season at Old Trafford. Ferguson also got ahead of Arsenal’s Arsène Wenger in 2003 when he moved rapidly and got Cristiano Ronaldo to Old Trafford after a friendly match between Sporting Lisbon and Manchester United in which the 17-year old Portuguese wizard had impressed the established stars of the Red Devils so much that legend has it they begged Sir Alex on the plane home from Portugal to buy the kid. The list goes on and on.

But if we look closer into the history of Ferguson’s transfer choices, especially during his last years at Old Trafford, we also see some (big) mistakes that are still haunting Manchester United and causing the club problems today. I have listed some of these mistakes here and prioritized them so the first one is the one with the potentially biggest negative impact on the club.

1) Paul Pogba

On December 31, 2011, on Ferguson’s 70th birthday, Manchester United played Blackburn Rovers at Old Trafford. Ferguson found himself in the midst of an injury crisis that saw him employ Michael Carrick, their normal midfield conductor, in central defense. The 18-year old Paul Pogba, whom United had signed from Lens in France a few years earlier, was eager to show the Scottish legend – famous for giving young players a chance – what he could do. But Ferguson opted to use right back Rafael and wide man Park Ji-sung in the United engine room. United were not only beaten 2-3 that day, they also lost what has since proved to be arguably the biggest talent in his generation, Paul Pogba.

Pogba’s United destiny was further sealed when Paul Scholes decided to return from his retirement to help Ferguson during his injury crisis only days after the Blackburn loss. In fairness, it should be noted that Paul Scholes has recently commented on Pogba’s lack of opportunities at United. Here he described Pogba’s displays in reserve matches as not really good enough to warrant a place in the first team. In addition, it should also be noted that some people think that financial issues played a huge role in persuading Pogba to join Juventus. However, the present situation still shows that Manchester United and Alex Ferguson let go of the most talented central midfielder when Pogba left Old Trafford.

2) Gerard Piqué

As with the Pogba case where the situation was basically a choice between Rafael and Pogba, Ferguson decided at some point during the summer of 2008, perhaps even earlier if we are to believe Piqué himself (he recalls a mistimed header against Bolton Wanderers on November 24, 2007 as the decisive moment when Ferguson stopped believing in him), that Jonny Evans and not Gerard Piqué represented “the future” of Manchester United. Here it is also worth mentioning that even though Ferguson sanctioned Piqué’s transfer to FC Barcelona and dubbed Evens “the future,” it is likely that Piqué would have ended up in Barcelona at some point anyway due to his childhood connections with the club and the city. But with Evans being on the brink of an Old Trafford exit this summer, Ferguson’s choice in 2008 does add itself to a list of haunting decisions he made in his final years.

3) Robert Lewandowski

In 2012, Alex Ferguson was on the lookout for a new proven striker. He had narrowed his search down to two. Either he would move for Arsenal’s Robin van Persie or Dortmund’s Robert Lewandowski. He chose Van Persie. The Dutch striker had a proven track record in the English Premier League and was as far from being a gamble as he could be. Ferguson was proved right at the time, because Van Persie was the decisive factor behind Manchester United’s championship a year later. Today, we may look upon Ferguson’s decision with another type of glasses. The Van Persie quick fix seemed a stroke of genius at the time. But with the problems Manchester United suffered in attack last year under Louis van Gaal, it has become urgent for the Dutch coach and Manchester United to provide Wayne Rooney with some back up or downright competition. Van Persie had his second uneven season in a row and huge question marks are hanging over his Old Trafford future at the moment. One cannot help wondering if Lewandowski would have been a better choice in 2012.

4) David de Gea

You may wonder what on earth makes me mention David de Gea on a list of Ferguson’s mistakes. No doubt has De Gea been a fantastic goalkeeper for Manchester United for two or three seasons, but I cannot help thinking that it was always in the cards that he would return to Spain if he established himself as a true world-class keeper.

Ferguson used to say how he regretted that he didn’t have the balls (maybe not exactly his words) to trust his instincts and place his trust in the very young Petr Cech. But he didn’t, and Cech ended up in Chelsea where he established himself as one of Premier Leagues best keepers, and he together with John Terry, Frank Lampard, Didier Drogba he personified the heartbeat of Chelsea for more than a decade.

Ferguson didn’t want to make the same mistake twice, so he identified the young De Gea as Edwin van der Sar’s long-term replacement and the future of Manchester United. But the difference is that whereas Cech comes from the Czech Republic, De Gea comes from Spain. There has never been any pulling of childhood club or country in the case of Cech while he has been up there among the best, but this is what is happening with De Gea. It would not have happened with someone like Thibault Courtois, who is now at (guess where!) Chelsea. My point is that De Gea would never go on to be a long-term solution at Old Trafford. If he failed he would be shown the door. If he succeeded, Real Madrid would come knocking on his door. And we already saw with Cristiano Ronaldo that they are very persuasive knockers when the player involved is from the South (of Europe or America).

5) David Moyes

Regardless of your name and your resumé, it would have been a tremendous task to succeed Alex Ferguson. But the choice of David Moyes – and the choice was Alex Ferguson’s alone – was a mistake. Moyes never at any moment showed that he had the soccer vision and the personal charisma to handle the job. Ferguson seldom had to explain to the fans and the media what his vision of good soccer was, because during the years, and as trophy after trophy kept piling up at Old Trafford, everybody knew what his style was. Even though he became a little less risky, especially in Europe, in his later years, people still associated Manchester United with attacking flow, width, and adventure. It was the Celtic romanticism in Ferguson that helped him decide that Moyes was the right man to take over from him. After all, they came from the same neighborhood, and Old Trafford has a pretty awesome history with Scottish managers. But Moyes’ working class roots had instilled cautiousness and defensiveness in him, whereas Ferguson’s had made him adventurous and hazardous.

It is easy to see how this list of five mistakes relates to the present situation at Manchester United. David Moyes’ short reign was close to becoming a disaster for the club. It may have proven difficult for any manager to take over from Ferguson, but no one expected them to drop from champions with an 11-point lead to seventh place. In contrast to Moyes, Louis van Gaal seems to have a very clear vision of how he wants Manchester United to play, and he seems to be able to communicate this vision to his players – and even to the media. In addition, his personality – read: big ego – seems to thrive in the spotlights of the Theater of Dreams. Most importantly, Van Gaal managed to get Manchester United back into the UEFA Champions League after one season without European soccer at Old Trafford, but even though he spent $233 million in his first transfer window (after Moyes had spent $100 million), a major reconstruction task is still ahead of Van Gaal.

Everybody agrees that what Manchester United need is a central defender à la Piqué, a central midfielder à la Pogba, and a striker à la Lewandowski, and if De Gea stays one more year he will most definitely depart for Madrid next summer.

It may be that United are already well equipped on the keeper position with Victor Valdes. But it is never good for a club and a player when transfer speculations are allowed to run for too long. Manchester United need to solve the De Gea situation quickly.

SEE MORE — Watch the Sir Alex Ferguson interview on the Charlie Rose Show.

This situation seems inextricably intertwined with their hunt for a central defender. It seems likely that Van Gaal will get his high priority world-class defender in Sergio Ramos, and that De Gea will then head in the opposite direction. If that happens, Van Gaal has made one important step towards making Manchester United genuine title contenders again.

SEE MORE — Sir Matt Busby and Santiago Bernabeu: A tale of two icons.

However, it will still take a central midfielder or two and a striker to realize that potential. It may not be Pogba returning as the prodigal son to Old Trafford, but if rumors are true both Morgan Schneiderlin and Bastian Schweinsteiger could arrive soon.

Even though the hugely talented Dutch winger Memphis Depay has already joined Van Gaal’s ranks, Manchester United are still in the hunt for firepower up front. It must be said, though, that Robin van Persie may very well end up staying one more season at Old Trafford. And he could have a fantastic season after a summer without the rigors of a World Cup. The most likely, however, is that United will make a move for someone like Harry Kane or Edinson Cavani.

Come September and Manchester United may have spent another $200 million, meaning that their transfers during the last one and a half year will have cost them more than half a billion dollars. Some of those, though not all of them, are down to Ferguson’s mistakes.