Manchester United have produced some great players in the past.
The club's infamous youth academy has produced footballers such as Ryan Giggs, Paul Scholes and David Beckham, players who all developed into world-beaters whilst at Old Trafford.
Manchester United have also grabbed the headlines by signing some of the biggest and most coveted stars in world football.
The signing of Eric Cantona from Leeds United was one that not only shocked the world but also helped Manchester United embark on a period of massive success.
During the reign of Sir Alex Ferguson, Manchester United signed the likes of Cantona, Ruud van Nistelrooy, Rio Ferdinand, Cristiano Ronaldo and Wayne Rooney to name a few.
All the aforementioned players helped the club maintain its status as one of the biggest clubs in the world during their time at United.
However, Manchester United have also had their fair share of big-name signings who have failed to live up to expectations.
These players endured massive dips in form and confidence after joining the Premier League giants, and were never able to rekindle their form after parting ways with the club.
On that note, let's take a look at 5 players whose careers dipped after joining Manchester United
#5 Shinji Kagawa
Shinji Kagawa joined Manchester United from Borussia Dortmund in the summer of 2012 in a deal worth £17 million.
The Japan international enjoyed two brilliant years with the Bundesliga giants before coming to Old Trafford. He helped the club win two Bundesliga titles, and scored 29 goals in 71 appearances in all competitions.
Manchester United were desperate to sign an attacking midfielder that summer and were buoyed by the signing of Kagawa.
The midfielder, however, struggled to come to grips with the speed and physicality of the Premier League. In his two seasons at United, he made 57 appearances and scored just 6 goals.
Kagawa returned to Borussia Dortmund in 2014 and went on to make another 145 appearances for the club over five seasons.
He was, however, unable to recapture the form he displayed during his first spell with the Bundesliga club, and is currently plying his trade with Greek club PAOK.
#4 Alan Smith
Alan Smith was once part of an attacking trio at Manchester United that included Wayne Rooney and Cristiano Ronaldo. Smith made the shock move from Leeds United to Manchester United in 2004 after Leeds were relegated from the Premier League.
Despite predominantly being a second striker, Alan Smith was often asked to play as an attacking midfielder for Manchester United. Playing out of position hampered Smith's progress at United.
After enjoying an impressive first season with the club during which he scored 10 goals in 42 appearances, Smith scored just two goals in his next 51 appearances for the Red Devils.
He moved to Newcastle United in 2007, and failed to score a single goal in his five seasons with the club.