#3 Signing Alexis Sanchez
Perhaps the biggest transfer flop in the Premier League in recent times, Alexis Sanchez being signed up by Manchester United, was one of the most ill-advised decisions the Red Devils have made in the transfer market.
Alexis Sanchez seemed destined to join Manchester City and it's almost clear to everyone now that Manchester United decided to hijack the move because they didn't want their direct rivals to be further strengthened.
Sanchez had no place in Jose Mourinho's side, which played a disjointed brand of football. The Chilean was paid an exorbitant amount in wages and his entry meant that the likes of Marcus Rashford and Anthony Martial were demoted from the starting XI.
Alexis Sanchez scored a total of five goals for Manchester United across all competitions before being initially shipped out on loan and then sold to Inter Milan. One of the best things that Ole Gunnar Solskjaer did after his first half-season as manager of Manchester United was to do away with players like Sanchez who were not a good fit for the club.
#2 Not backing Jose Mourinho in the transfer market
Jose Mourinho guided Manchester United to a second-placed finish in his second season in charge of the club. He then went on to undermine his players by saying that it was his greatest achievement as a manager despite having won multiple trophies all around Europe.
To give Mourinho the benefit of the doubt would be to concede that he was indirectly asking to be backed in the summer transfer window. On the back of a decent league campaign, that is what was expected of the Manchester United board as well.
However, Ed Woodward chose not to get Mourinho his transfer targets and ended up signing Fred, Lee Grant and Diogo Dalot and this greatly soured the relationship between the manager and the club's top brass as the 'Special One' was particular about buying a solid centre-back.
Jose Mourinho's frustration boiled over and it eventually led to his sacking.
#1 Signing up for the European Super League
It's interesting to note that despite making so many poor decisions over the course of the past decade, nothing outlines the disconnect between Ed Woodward and the fans like his signing Manchester United up for the European Super League.
The European Super League fiasco will go down in history as a milestone event in modern day football and it goes to show how powerful the fans' voice is and how relevant it is even today. It was also the final nail in the coffin and there was no escape from it and it obviously had a lot to do with Woodward resigning.