Traditionally, when a top soccer club decides to purchase a new player, they do so with the intention of adding depth to their squad or strengthening certain areas of their game. From Real Madrid's iconic purchase of David Beckham from Manchester United to recent acquisitions such as Barcelona's purchase of Philipe Coutinho, we have seen loads of teams reap the benefits of an effective transfer.
Unfortunately, transfers don't always go as expected, as prospective stars do sometimes underperform and let down even their most hardcore fans. Let's take a look at some of the players who have unfortunately failed to live up to expectations.
10 Freddy Adu
Once dubbed 'The Next Pele', the American midfielder's career started with a bang. He signed with MLS giants DC United at the tender age of 14, and received a trial with Manchester United at age 16, where United manager Sir Alex Ferguson stated that "He is a talented boy".
Unfortunately, his career took a turn for the worse after signing for Portuguese side Benfica, where he struggled to get game time and often went out on loan. He has since lost his place in the American National Team and has returned to the MLS, signing for Las Vegas Lights after spending three months without a club.
9 Nicklas Bendtner
The Danish forward showed much promise in his debut season for Arsenal after receiving a call-up from the reserves. While he played a critical role in the Arsenal lineup for four seasons, a slump in form saw The Gunners loan him out to Sunderland.
This marked the end of "Lord Bendtner's" Arsenal career, as he struggled to regain a spot in the starting lineup. What followed were brief stints at Juventus and Wolfsburg, after which Bendtner was left a free agent.
Desperate for playing time, he signed for minnows Nottingham Forest before transferring to Norwegian side Rosenborg. Additionally, he was left out of Denmark's 2018 World Cup squad due to injury.
8 Carlos Kaiser
The Brazilian striker is commonly known as the biggest conman in world soccer. This is because he never actually played a match in his entire career. Upon signing for Mexican side Puebla at age 16, Carlos discovered that he didn't actually enjoy playing soccer. For this reason, he would pretend to suffer from muscle pain so that he couldn't be selected to play.
Kaiser also conned numerous professional teams in Brazil, Mexico, the USA, and France to sign him by showing them fake videos of him playing, where he would pay spectators to chant his name. Naturally, his transfer would reap no benefits as he upheld his facade.
7 Gabriel Obertan
Many had high hopes for the French winger when he was purchased by Manchester United in 2009. Unfortunately, Obertan's potential was never realized, and he only scored one goal in 27 appearances before being transferred to Newcastle United.
He showed no improvement at Newcastle, and only scored three goals. This prompted The Magpies to release him from his contract. He then went on to make 12 appearances for Wigan Athletic, after which he played nine times for Russian outfit Anzhi Makhachkala. He has since faded into obscurity and now plays for Bulgarian side Levski Sofia.
Yet another Manchester United transfer that went awry. The Portuguese winger only made two league appearances from the bench before he went out on a series of loans and eventually departed from the Red Devils. So poor was his time at Man United, that "no one seems to want to take responsibility for United's decision to take a punt on an untested forward". It is even rumored that Sir Alex Ferguson had never seen the Portuguese National play before signing him.
5 Stephen Ireland
The Irishman became the center of attention during a Euro 2008 qualifier for the Irish national team, where he scored the winner in a 1-0 win over Wales. This caused many in world soccer to think that he would become the next Irish sensation.
Unfortunately, he never fulfilled his potential as he was soon cut from the national team after attempting to get compassionate leave through false means. Poor performances on the pitch saw Manchester City transfer him to Aston Villa. Eventually, he went to Stoke City on a free, who released him four years later. He currently plays for Bolton Wanderers in lower league soccer.
4 Bojan Krkic
Once dubbed "the Next Messi", Bojan is a long way away from his glory days. He scored the winner on his Champions League debut, and also became the youngest player to score for Barcelona in La Liga aged 17 years seven months and four days. He impressed at international level too, scoring the winning goal for Spain in the Under-17 European Championships.
Unfortunately, Bojan started to struggle at Barcelona upon the departure of manager Frank Rijkaard. He never recovered, and can now be seen playing for Stoke City in the EFL Championship, where he has only started three games this season.
3 Fabio Coentrao
The Portuguese left-back had a decent career for many years, having played for the Portuguese national team in the 2010 and 2014 World Cups as well as Euro 2012. His impressive performances earned him a transfer to Real Madrid in 2011, however, a failure to integrate into the Galacticos squad saw him sent out on loan numerous times.
Upon returning to Real Madrid, a hamstring injury saw him only make three appearances in the 2016/17 season. He was later sold back to boyhood club Rio Ave FC, and justified the move to a smaller club by explaining, "There is no money that can pay for happiness. I was born poor. I don't mind dying poor.”
2 Renato Sanchez
The Portuguese winger shocked the world with an incredible performance for Portugal during Euro 2016. Not only was he man of the match against Croatia, but he also scored a decisive goal in the quarter-final clash with Poland. Such impressive results attracted the interest of Bayern Munich, who signed him soon after.
Upon being loaned out to Swansea for a season, his fortunes soon changed. He only made twelve appearances in the Premier League and failed to score a single goal or make an assist. Upon returning to Bayern this season, he has still not regained his form, and his goal drought lingers on.
1 Richard Dunne
Dunne had an action-packed career playing at Everton, Manchester City, Aston Villa, and QPR, and was also made the captain of the Irish national team. The one thing Richard Dunne's career lacked, however, was silverware, as he never managed to win a major trophy at top-flight level.
On top of this, Dunne holds the Premier League record for most own goals at 10. As if this wasn't enough, his poor disciplinary record resulted in another Premier League record of eight red cards. Whilst the current BT Sports pundit will be remembered for years to come, it may be for all the wrong reasons.