Goalkeeper - Massimo Taibi It was always going to be hard following Peter Schmeichel however not quite as hard as Taibi made it look. United paid £4.4m for him in 1999 which in the end worked out at just over £1m per first team appearance. Taibi had a disastrous opening four games for the club, flapping at a free kick on debut and allowing Sami Hyypia to score as well as conceding five against Chelsea and committing one of the worst goalkeeping blunders of all time as he allowed a tame Matt Le Tissier shot to roll straight through his legs - something he blamed on his spikes. They were to be his only four games for the Red Devils.
Defence - William Prunier
Prunier had come through the Auxerre youth system with Eric Cantona however he did not share quite as an illustrious Man United career, managing just two first team appearances for the club. Ferguson brought him in on a trial with the intention of evaluating him in a few reserve team matches however he was hit with an injury crisis and Prunier was thrust into the first team. His club debut came against QPR where he was reasonably impressive however his second appearance did not go so well. United conceded four goals in a humiliating defeat by Tottenham and Prunier was singled-out for blame. He wasn't offered a permanent deal by Ferguson and returned to Europe.
Defence - Pat McGibbon The Northern Irish defender was labelled as one of the stars of the youth team however he managed just one appearance for the club in what looked like an easy League Cup tie against York City in 1995. Unfortunately for McGibbon he was sent off and Manchester United crashed to a shock 3-0 defeat. He spent the next two seasons on loan before leaving for Wigan in 1997, still not having played a full 90 minutes for the club.
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Right Midfield - Jordi Cruyff Having a legendary father widely regarded as one of the best to play the game must be quite a hard act to follow, however Jordi did have the advantage of growing up and learning football in Barcelona and even broke into their squad while his father was manager. His United career was not successful, he failed to establish himself as a first team regular and made only 55 appearances in four years. Despite playing during one of the club's most successful periods he picked up only one winner's medal. He scored a paltry eight goals during his time at the club and eventually was shipped off to Alavés.
Midfield - Eric Djemba-Djemba According to the chants the Cameroonian was 'so good they named him twice', unfortunately this proved to be painfully ironic for United fans as the midfielder signed as Roy Keane's heir failed to establish himself at the club. He managed only 20 league appearances for the club and within 18 months he was on his way to Aston Villa where he similarly failed to impress. Off the pitch he was known for his ridiculously excessive spending and reportedly had a fleet of ten 4x4 cars and 30 different bank accounts. By the age of 26 he was playing his football in Qatar.
Midfield - Kleberson Kleberson's performances at the 2002 World Cup led to his coach Phil Scolari declaring him the driving force behind Brazil's win and Ferguson signed him for £6.5m at the same time as Cristiano Ronaldo. However his career took a slightly different path to the Portuguese winger and the Brazilian, who had been signed as a replacement for the equally unsuccessful Juan Sebastian Veron, managed only 20 appearances for the Red Devils before being sold to Besiktas.
Left Midfield - Ralph Milne The man Ferguson himself labels as his worst ever signing despite only setting him back £170,000 is almost totally unheard of, largely because he failed to impress at United, contributing almost nothing on the pitch. In some ways he was the second coming of George Best unfortunately this was restricted to his activities off the pitch and Milne recently admitted he squandered most of his money on alcohol, women, and gambling. United was to be his last professional club in England.
Forward - David Bellion The signature of Bellion was a controversial one with Ferguson allegedly tapping him up while still under contract at Sunderland. A £2m out-of-court settlement was reached but in the end Ferguson must have wished he hadn't bothered as the Frenchman scored only four goals in 24 appearances before eventually being shipped off to Nice having failed to establish himself as a first team regular.
Forward - Diego Forlan There is no doubting Diego Forlan's class, the Uruguayan was the winner of the Golden Ball for the best player in the 2010 World Cup as he helped his team to a highly respectable fourth place and he scored an enormous amount of goals in the Spanish league for Villareal and Atletico Madrid before his move to Inter Milan this summer. However his time at United was not a success. It took him an incredible eight months and 29 games to score his first goal for the club and in his three years at Old TRafford he managed only 17 in 63 appearances. He even struggled with celebrating his goals - he took his shirt off after scoring against Southampton and was unable to put it back on in time for the restart. The arrival of Wayne Rooney coincided with his departure from the club.
Forward - Dong Fangzhuo The first Chinese player to feature for United was signed in January 2004, however due to work permit restrictions he was unable to actually play for the Red Devils until 2006 and it wasn't until over three years after his signing that he made his debut for the club, at the end of the season, with the title already won. He made a substitute appearance in the Champions League and played an entire League Cup game as United lost to Coventry City but that was it. Dong failed to be given a squad number for the 2008-9 season with his number being given to Rafael da Silva and his contract was mutually terminated by the club so that he could find first team football elsewhere.
Sir Alex Ferguson is to bow out as Old Trafford supremo - but it hasn't all been a bed of roses.
He is the longest serving manager in world football and during those years has nurtured some of the finest footballing talent to hit the world stage. However, Sir Alex hasn't always got it right.
Here, we present a 'Worst XI', a selection of United players that even Ferguson couldn't make the best of.
Do you agree with our selection? Who would be in your 'Worst XI'? Leave your thoughts and comments below...