Manchester United are the most successful English football team in history and one of the true global powerhouses when it comes to both results and finances. It is estimated that the Old Trafford club now have 659 million fans worldwide and are valued at $3,104 M by American business magazine Forbes.
On the field, the team has spent most of their existence in the English top flight and despite their recent downturn in performances since Sir Alex Ferguson's departure, have won the league a total of 20 times and lead the way ahead of eternal rivals Liverpool.
The club has also won the F.A. Cup a total of 11 times and the Champions League on three occasions with their last coming in Moscow in 2008 after United defeated Chelsea on penalties after John Terry's famous slip on the Luzhniki turf.
Some wonderful players have pulled on the iconic red shirt during the club's history including the likes of Sir Bobby Charlton, George Best, Bryan Robson, Ryan Giggs and Cristiano Ronaldo to name just a few.
Given the club’s illustrious history and constant desire to improve and win, generally only the very best players make it into the first team and stay there. Some lose their way and disappear with some fantastic players not even making a solitary first team appearance.
Here we take a look at the Top 15 players who never made it at Manchester United:
15 Ron-Robert Zieler
German goalkeeper Ron-Robert Zieler joined Manchester United in 2005 at the age of 16 and played for their youth and reserve squad without ever making a first team appearance for the club.
It was always going to be an impossible feat to dislodge Edwin van der Sar from between the sticks and after a brief loan spell with Northampton Town, the goalkeeper was allowed to return to Germany with Hannover 96 in April 2010.
Zieler was handed his Hannover and Bundesliga debut on 16th January 2011 in an game away at Eintracht Frankfurt and has kept his place in the team ever since.
His excellent club form meant that he was called up to the Germany squad to compete at the World Cup in 2014 as back-up to first-choice Manuel Neuer and Roman Weidenfeller. Although the former Manchester United youth failed to make an appearance during the tournament, he now has a World Cup winners medal after his country defeated Argentina in the final.
14 Robbie Savage
Former Wales international Robbie Savage went on to have a successful career in English football after his release from Manchester United. The midfielder represented six clubs during his playing days and went on to play over 600 career games before retiring in 2011 to pursue a career in the media.
Savage started his career as a striker in his days at Old Trafford before switching to the midfield role that we know him for on leaving the club.
The Welshman played in the FA Youth Cup winning team of 1992 alongside Gary Neville, Ryan Giggs, Nicky Butt and David Beckham before leaving the club for Crewe Alexandra in 1994 after failing to make an appearance for the first team.
13 Ravel Morrison
Englishman Ravel Morrison featured in three first team games, all in the League Cup, when Sir Alex Ferguson was still in charge of the Old Trafford club with his last coming in the 2011–12 season.
Ferguson claimed that the attacking midfielder was the best 14-year-old he had ever seen when watching the youngster, however after several off-field issues that ended with criminal charges and a contract dispute, Morrison was allowed to leave the club on the winter transfer deadline in 2012.
West Ham United signed the highly-rated but troubled youngster for a nominal fee and after several loan spells and a few excellent games for the London club, Morrison was again on the move after his contract was terminated.
Serie A club Lazio swooped for the player's signature in the July of this year with Morrison having made just three appearances for his new club to date.
12 Jovan Kirovski
Former USA international was the first American to sign with Manchester United when he joined the youth ranks in 1992 but unfortunately never made the breakthrough to the first team due to work permit problems.
Sir Alex Ferguson rated the Californian highly and after scoring 20 goals in 21 reserve team outings in the 1995-96 season, he was expected to be granted a permit and possibly break into the first team.
However, it was not to be and Kirovski moved to Borussia Dortmund where he remained for four years. A year in Portugal with Sporting Lisbon followed and after another few years back in England, the striker signed with Los Angeles Galaxy.
Kirovski went on to win two MLS Cups with Los Angeles Galaxy and scored nine goals in 62 appearances for the USA national team.
11 Radamel Falcao
Already a global superstar by the time he signed for Louis van Gaal's United in the 2014-15 season, Falcao unfortunately failed to live up to his name and price-tag whilst on loan from Monaco.
United signed the Colombian striker in a £6 million loan deal with an option to sign permanently for £43.5 million at the end of the season.
Before a cruciate knee injury ruled him out of the 2014 World Cup, the striker nicknamed El Tigre had scored 155 in 200 games in European football and was expected to be a huge success in the Premier League.
With United going through a difficult time and the striker lacking match fitness, he only managed to score four goals in 29 appearances before the club rejected the chance to sign him on a permanent deal.
Portuguese forward Bebé signed with Manchester United in a shock £7.4 million in 2010 with both media and fans alike wondering who the player was with even Sir Alex Ferguson admitting that he had never seen Bebé play before signing him.
After signing with United from Vitória de Guimarães, the player found his chances limited and after several loans back in his homeland, he left United for good in July 2014 when he signed for Lisbon giants Benfica.
In his four years at Old Trafford, Bebé only managed to feature in seven games scoring two goals against Wolverhampton Wanderers in the League Cup and Bursaspor in the Champions League.
9 Phil Bardsley
Scottish international defender Phil Bardsley made 18 appearances in five seasons for United before leaving the club for Sunderland in 2008.
With Bardsley having to compete against Gary Neville for the United right-back spot, his chances were always going to be limited, so he was sent out on loan five times during his stay in Manchester.
While on loan, the youngster played in Belgium, Scotland and the English leagues before United decided to let him go permanently in a £2.10m.
After heading further north in 2008 with Sunderland, Bardsley claimed the right-back position for himself and made a total of 200 appearances for The Black Cats before joining Premier League rivals Stoke City in 2014.
8 Diego Forlán
Uruguayan international Diego Forlán signed from Argentinian club Independiente in 2002 to bolster the attack alongside Ruud van Nistelrooy and Ole Gunnar Solskjær.
The striker never really found his feet in Manchester despite playing almost 100 games for the club. Although Forlán couldn't be considered as a success for United, he did endear himself to the fans with a brace in December 2002 in a 2-1 away win at Premier League rivals Liverpool.
After leaving Old Trafford, Forlán went on to become on of the most feared strikers in Europe with Villarreal, Atlético Madrid and Inter Milan, winning several team and individual awards in the process.
From Milan, Forlán had fairly prolific spells in Brazil and Japan before returning to his native Uruguay to join boyhood club Peñarol.
7 Danny Higginbotham
Defender Danny Higginbotham signed a two-year professional contract with Manchester United in 1998 after sufficiently impressing in the youth squads. The Manchester native went on to make his debut in the same year against Barnsley in a 2-0 away win.
Higginbotham was then loaned out to Royal Antwerp where he became somewhat of a fan favorite. Although the defender did well in Belgium, he was banned from football for a year alongside team-mate Ronnie Wallwork for an altercation with a referee.
After a legal battle, a Belgian court reduced Higginbotham's ban to four months and was subsequently handed a new contract by his club. In his last season in Manchester, the player made six appearances before deciding to leave to get first-team football.
After leaving United, Higginbotham had a relatively successful career making 450 professional appearances and three for the Gibraltar national team before retiring in January 2104.
6 Ryan Shawcross
After signing with the Manchester United youth team in 2002, Ryan Shawcross went on to play just two senior games for the club, both in the League Cup in 2006.
The highly-rated defender then spent a year out on loan at Royal Antwerp before joining Stoke City in a similar deal in 2007. The player impressed during his loan spell with Stoke putting in a £1 million offer for Shawcross which was accepted in January 2008. The deal was completed and eventually rose to £2 million with United having first refusal on the play should a transfer bid come in.
Shawcross has gone on to be such a key player for the Potters that he was given the captaincy for the 2010–11 season which he still holds and went on to win an England cap in 2012 against Sweden.
5 Giuseppe Rossi
American-born Italy international Giuseppe Rossi joined Manchester United as a 17-year-old from Italian club Parma in 2004 before going on to make his first team bow in the November.
Rossi, who was extremely well thought of by the Old Trafford staff, joined Newcastle United and later Parma to gain first-team experiences while his chances in Manchester were limited.
On returning to Manchester, Rossi was sold to Villarreal in a surprise £7 million deal where he became a prolific goal-scorer for the team. Since his first cruciate ligament injury in 2011, the player hasn't been the same and has suffered several injury plagued seasons.
Even so, it didn't stop Fiorentina signing the player in 2013. Since that date, the striker has managed just 28 games for his club with a goal return of 18.
4 David Platt
Current head coach of Indian club FC Pune City, David Platt started his career with Manchester United upon leaving school in July 1984. The midfielder unfortunately didn't make the grade at the club and was given a free transfer in February 1985.
On leaving United, Platt was quickly snapped up by Crewe Alexandra where he started to make his name as a goal-scoring midfielder. After three years with the club, he moved on to Aston Villa before a four year stint in Italy with Bari, Juventus and Sampdoria.
Platt returned to England in 1995 with Arsenal where he won the league and cup double in the 1997–98 season.
Although Platt was rejected by United, he went on to become an important England regular, winning 62 caps during his career. Perhaps his best moment in an England shirt came in the 1990 World Cup when he scored a wonder goal versus Belgium.
3 Peter Beardsley
Former England schemer Peter Beardsley made just a solitary appearance for Ron Atkinson's Manchester United in 1982 after a £250,000 transfer from Canadian outfit Vancouver Whitecaps.
The player couldn't break into the first team and hopped back over the Atlantic just a few months later after being released on a free transfer in March 1983.
It may have been a mistake for the club to let him go as Beardsley went on to become a star player for Newcastle United, rivals Liverpool and Everton before ending his career in Australia with Melbourne Knights.
Beardsley played 59 times for the England national team and 237 goals in almost 800 club games as a professional.
2 Gerard Piqué
Since leaving Manchester United for Barcelona in May 2008, Gerard Piqué has established himself as one of the best and most decorated defenders in the world.
Sir Alex Ferguson signed the defender from boyhood club Barcelona in 2004 before he signed a professional contract with the Catalan giants which meant there was no transfer fee involved.
In four seasons in Manchester, Piqué played just 23 games before being rejoining Barcelona for a £3.5 million fee - a snip for the team who were looking for a long term replacement for Rafael Márquez and Carles Puyol.
Piqué immediately became a first team regular and has now won a total of 20 major honors during his eight seasons back in Spain.
1 Paul Pogba
French international Paul Pogba signed with United in a highly controversial transfer from Le Havre in October 2009 whereby the club accused United of signing the player in an underhand way.
Initially, Pogba played in the youth ranks where he helped United to claim their 10th Youth FA Cup before being promoted to the senior squad ahead of the 2011–12 season. Pogba managed to play seven games during the season before joining Italian side Juventus.
In July 2012, United manager Sir Alex Ferguson confirmed that Pogba had left the club after not renewing his contract and joined Juventus on a free transfer. Ferguson believed that the player and his agent had disrespected the club in asking for too much during contract negotiations.
Since signing for Juventus, Pogba has gone on to become one of the best midfielders in the world, winning three Serie A titles and one Coppa Italia while in Italy.