#6 Fernando Torres | £50m (2011)
Fernando Torres might go down as one of the worst big-money signings in Chelsea history.
However, the sight of the Spaniard running at a hapless Victor Valdes between the sticks for Barcelona to score the goal that sealed Chelsea’s place in the final of the UEFA Champions League in 2012 will forever be remembered by the Blues supporters.
Following his move from Atletico Madrid to Liverpool, where Torres scored a mind-boggling 81 goals in 142 games, Chelsea broke their transfer record to complete a shocking deadline-day move for the Spaniard.
Torres, who was arguably the best striker in the league prior to the move, struggled to find form in front of goal, though.
His time with Chelsea was riddled with several missed sitters, including a shocking miss against Manchester United.
The Spaniard would score just 20 goals in 110 Premier League games for the Blues, and in 2016, he parted ways with Chelsea after loan spells with AC Milan and Atletico Madrid.
Three years later, he hung up his boots following a short spell in the Chinese Super League.
#5 Jorginho | £50m (2018)
In 2018, Chelsea beat Premier League rivals Manchester City to the signing of Napoli’s midfield regista Jorginho for a reported £50m fee.
The father-son relationship between then-Chelsea coach Maurizio Sarri and the midfielder might have played a huge role in securing the deal after they enjoyed a cordial relationship during Sarri’s one-year spell in charge of Napoli.
With Sarri bringing his eye-catching possession-based style of play to Stamford Bridge, he opted to sign Jorginho, who was at the heart of his tactics back in Napoli.
However, after Sarri moved back to Italy to take charge of Juventus, Jorginho struggled for minutes under the newly-appointed Frank Lampard, who preferred a midfield pivot of tireless midfielder N’Golo Kante and Mateo Kovacic.
This season, Jorginho has been a star performer at the centre of the park for Chelsea, though. He currently leads the Blues' scoring charts in the Premier League with six goals, albeit all from the penalty spot.
Playing alongside Kovacic, he has formed a lethal partnership in midfield and is proving to be a key player for Chelsea in the Thomas Tuchel era.
#4 Christian Pulisic | £58m (2019)
Chelsea snapped up Christian Pulisic from Borussia Dortmund for £58m in the 2019 winter window and immediately loaned him back to complete the season with the Black and Yellows.
Although the fee initially raised a few eyebrows, considering Pulisic's age and lack of experience, he was viewed as a potential replacement for Eden Hazard, who was certain to quit the club at the end of the season.
However, Pulisic has shown signs he can be a world-beater, after a series of stellar performances for the Blues.
While he has struggled with several injuries since joining Chelsea, when fit he has shown that he can fill the large boots of Eden Hazard and single-handedly turn a game on its head for Chelsea.
Pulisic inspired Chelsea to Champions League qualification last season, scoring five goals after the restart of the Premier League.
Following the departure of Brazilian star Willian, Pulisic picked up the number 10 shirt, donning the famous number of former Chelsea star Eden Hazard.