Chelsea have an interesting transfer policy which is rarely used by Premier League clubs. They buy players at a very young age and send them out on loan to develop. If these players perform well during their loan stint, then they may have a chance of playing for the first team in the future.
The likes of Thibaut Courtois, Kevin De Bruyne and Romelu Lukaku were all signed at a very young age before they were loaned out for regular playing time.
The Blues also have an academy that has produced a lot of promising youngsters but their pathway into the first team is not easy given the quality of Chelsea’s squad. Chelsea’s academy team have won the FA Youth Cup seven times in the last nine seasons including the last five in a row!
A plethora of talented youngsters were contracted to Chelsea before they moved elsewhere to further their ambitions.
When you take such players into consideration and also some notable senior players Chelsea have sold in recent years, you get a pool of players big enough to make a side capable of winning the Premier League.
On that note, take a look at this incredible XI featuring players sold/released by the Blues in recent years and are currently active.
Goalkeeper - Thibaut Courtois (Real Madrid)
Thibaut Courtois is one of the few players who benefitted from Chelsea’s loan policy. He joined Chelsea in 2011 aged 19 and immediately went on loan to Atletico Madrid as a replacement for David De Gea.
Courtois was on loan at Atletico Madrid for three seasons during which he played 154 games, won four titles including the league title and he also claimed the Zamora Trophy twice.
The Belgian returned to Chelsea as their first choice goalkeeper before the 2014/15 season. In the four seasons that followed he played 154 games, won four more titles including the Premier League on two occasions.
Courtois left Chelsea in the summer to join Real Madrid for £35m and Chelsea replaced him with Kepa Arrizabalaga for a world record transfer fee.
Honourable mentions - Petr Cech (Arsenal) and Asmir Begovic (Bournemouth)
Fullbacks - Branislav Ivanovic (Zenit Saint Petersburg) and Filipe Luis (Atletico Madrid)
Branislav Ivanovic joined Chelsea in January 2008 from the Russian Premier League and when he arrived at the club he was a centre-back by trade. However, the Serb predominantly played as a right-back during his stint in the Premier League.
Ivanovic played 377 games for Chelsea scoring 34 goals. In fact, he had a knack for scoring crucial goals throughout his Chelsea career. When he left Chelsea in February 2017, he had won 10 trophies with the Blues including every major domestic honour.
Filipe Luis was at Chelsea for only one season. He played 26 games during the season, won the Premier League and League Cup before returning to Atletico Madrid.
The Brazilian left-back has spent most of his playing career with Atletico Madrid. With the Spanish club, he has won six honours and has represented them in 301 games.
Honourable mentions - Ryan Bertrand (Southampton) and Patrick van Aanholt (Crystal Palace)
Centre-backs - John Terry (Free agent) and Nathan Ake (Bournemouth)
The former Blues captain represented the club in 717 games scoring 67 goals between 1998 and 2017. This places him third in the club’s all-time appearance list.
Terry won 16 honours with Chelsea during his long stint with the club and he won every possible domestic honour while he was there. In 2017, he decided to leave Chelsea up on the expiry of his contract and he dropped down a division to help Aston Villa gain promotion to the Premier League.
The 37-year-old left Aston Villa at the end of the 2017/18 season after they failed to gain promotion. Terry, however, hasn’t retired nor has he joined a new club.
Nathan Ake is another player who joined Chelsea at a very young age before going on loan multiple times and eventually leaving the club on a permanent deal.
The Dutchman joined the Chelsea youth system in 2011 aged 16 and made his first team debut aged 17 in December 2012.
Ake went on loan to Reading, Watford and Bournemouth during his stint with Chelsea. He made 17 appearances for the Blues, won the Europa League and League Cup, and was also named the Chelsea Young Player of the Year in 2012/13.
The 23-year-old left Chelsea in 2017 to join Bournemouth on a permanent deal and he has been a crucial member of the Cherries backline since.
Honourable mention - Jeffrey Bruma (Wolfsburg)
Midfielders - Nemanja Matic (Manchester United) and Kevin de Bruyne (Manchester City)
Nemanja Matic had two separate stints with Chelsea. He first joined Chelsea in August 2009 but played just three games for the club before leaving in January 2011 to join Benfica as a part of the deal that brought David Luiz to Chelsea.
Three years after he left Chelsea, Matic rejoined the Blues for £21m, went on to play 151 games for them and played a crucial role in winning two league titles.
The Serb was sold to Manchester United in 2017 following in the footsteps of Juan Mata.
Kevin De Bruyne joined Chelsea from Genk in January 2012. He spent the 2012/13 season on loan at Werder Bremen before returning to Chelsea.
De Bruyne left Chelsea in January 2014 to join Wolfsburg after failing to get regular game time. At Wolfsburg, De Bruyne realised his potential and ended the 2014/15 season with 16 goals and 27 assists in all competitions. In addition, he was named the Bundesliga Player of the Year.
The Belgian midfielder joined Manchester City in the summer of 2015 for a then club-record £55 million. He has played 142 games for the CItizens scoring 35 goals and has so far won the league and league cup twice.
Honourable mentions - Ramires (Jiangsu Suning), Oriol Romeu (Southampton), John Obi Mikel (Tianjin TEDA), Nathaniel Chalobah (Watford), Oscar (Shanghai SIPG) and Juan Mata (Manchester United)
Wingers - Mohamed Salah (Liverpool) and Andre Schurrle (Fulham)
Chelsea signed Mohamed Salah in January 2014 when the Egyptian was close to signing for Liverpool. He played 19 games for them and scored 2 goals before he was sent on loan Fiorentina.
Salah hit the ground in the Serie A and he eventually joined Roma on a permanent deal. He scored 34 goals in 83 games for the Italian giants before signing for Liverpool in 2017.
The 26-year-old had an unbelievably good season for the Reds and broke the Premier League record for most goals in a single season by scoring 32 goals in 36 league games. In all competitions, he scored 44 goals in 52 games.
Andre Schurrle joined Chelsea for £18m in the summer of 2013. He was at the club for a season and a half scoring 14 goals in 65 games before returning to the Bundesliga with Wolfsburg.
The World Cup winner moved to Borussia Dortmund in 2016 before returning to the Premier League with another London club in Fulham this summer.
Schurrle won the Premier League with Chelsea in 2014/15 although he was at the club for only half the season.
Honourable mentions - Juan Cuadrado (Juventus), Bertrand Traore (Olympique Lyon), Thorgan Hazard (Borussia Monchengladbach) and Christian Atsu (Newcastle United)
Strikers - Diego Costa (Atletico Madrid) and Romelu Lukaku (Manchester United)
Chelsea signed Diego Costa ahead of the 2014/15 season by paying the £32m buy-out clause in his contract. The Brazil-born Spain international scored 59 goals in 120 games for Chelsea and played a crucial role in winning the Premier League twice.
Costa fell out with Antonio Conte and that resulted in him being frozen out of the squad before the 2017/18 season. The 29-year-old returned to Atletico Madrid in January 2018 and helped them win the Europa League.
Romelu Lukaku joined Chelsea in 2011 aged 18 from Anderlecht and before he joined Chelsea, he already scored 41 goals in 98 games for the Belgian giants.
Lukaku only played 15 games for the Blues and never scored a goal for them. However, during his time with Chelsea, he went on loan to West Brom and Everton scoring 33 goals in 71 games before eventually joining the latter on a permanent deal.
Lukaku scored 87 times in 166 games for Everton in four seasons before making a £75m move to Manchester United in the summer of 2017 even though there was interest from Chelsea to resign the player.
Honourable mentions - Daniel Sturridge (Liverpool), Samuel Eto’o (Free agent), Fernando Torres (Sagan Tosu) and Dominic Solanke (Liverpool)