Dong Fangzhuo - DL Shide: Was on Manchester United's books for four-and-a-half years but spent three of those at Royal Antwerp. Had an impressive scoring record for the Belgian club but was out of his depth at United. Finished his career in China with Hebei Zhonji in 2014.
Louis Saha - Fulham: After 42 goals in 124 games for United, Saha left for Everton in 2008. He spent time at Spurs and Sunderland before retiring in 2013 following a short loan spell at Lazio.
Nemanja Vidic - Spartak Moscow: United's most fruitful January window to date saw them bring in Vidic and Patrice Evra 13 years ago. He was the best defender in the world for much of his time at United before joining Inter Milan in 2014 and retiring two years later.
Patrice Evra - Monaco: Evra spent the same amount of time at United as Vidic before also leaving for Italy, joining Juventus. Spells at Marseille and West Ham followed before his retirement earlier this year. Returned to United briefly earlier this year for help with his coaching badges.
Henrik Larsson - Helsingborg: The only loan signing on this list, but notable enough to be worthy of a mention, Larsson contributed to United's Premier League title success in 2007. He spent just two-and-a-half months at the club and would later say the only regret of his career was not staying at Old Trafford for longer. Retired from playing in 2013 before going into management. Was the manager of Swedish side Helsingborg up until September this year.
Rodrigo Possebon - Internacional: Had a lofty reputation following his arrival from Brazil but never fulfilled his potential before returning to his home country with Santos in 2010. Last played for Ho Chi Minh City in China.
Manucho - Petro Luanda - Angolan forward Manucho played just three times for United, spending time on loan at Panathinaikos and Hull City during his spell at the club before joining Real Vallodolid in 2009. Now without a club having most recently been at UE Cornella in Spain.
Zoran Tosic - FK Partizan: Arrived into a United team full of superstars and didn't make the grade. Ahead of his return to Old Trafford with FK Partizan last week, he admitted he wasn't quite ready to make the step up. Has carved out a respectable career for himself.
Ritchie de Laet - Stoke City - Another young arrival who failed to make the grade at United, De Laet is now at Royal Antwerp. Won the Premier League with Leicester in 2016.
Anders Lindegaard - Aalesund: One of the better signings on this list, Lindegaard was David de Gea's understudy for the majority of his United career, briefly replacing him as United's No.1 during the 2012-13 campaign. Now at Helsingborg, having been signed by Henrik Larsson in the summer.
Frederic Veseli - Manchester City: Never played for United, leaving the club for Ipswich in 2013. Now at Empoli in the Italian second tier.
Paul Scholes - Free agent: Had retired at the end of the previous season but laced his boots back as United vied for the title with City. Retired for good at the end of the following season. Had a brief spell in management with Oldham earlier this year but is now back in his role as a pundit with BT Sport.
Wilfried Zaha - Crystal Palace: United signed Zaha before loaning him back to Palace for the remainder of the 2012-13 season. When he eventually did move to United, it didn't work out. He returned to Palace on loan before re-signing for the Eagles permanently in 2015. Was linked with Arsenal in the summer but remains a Palace player.
Juan Mata - Chelsea: The only player in this list still at United. Mata is no longer a first-team regular but has proved he can be an effective squad player.
Alexis Sanchez - Arsenal: Arrived to much fanfare but flopped spectacularly. After 18 months at the club he was sent to Inter Milan.