Feeling the Blues: Ten former Chelsea men who shone elsewhere
Not as well-known as compared to the rest in this list, Cork was yet another product of Chelsea’s famed youth academy who failed to make the cut.
The defensive midfielder never got a chance in the first-team set-up during his five seasons at the club, and eventually left for Southampton in 2011.
There, he established himself as a solid and reliable midfielder, making over 100 appearances in four seasons, before moving on to Swansea.
Cork is now at Burnley, enjoying his football under Sean Dyche and has proven to be a solid signing for the Clarets.
The Serbian midfield general was initially deemed too raw to make the grade at Stamford Bridge, leaving Chelsea in 2011, as part of a swap deal for David Luiz.
It was at Benfica where his career started to take flight, under the tutelage of then manager Jorge Jesus, who had the faith to instil Matic as a first-team regular.
Matic was indispensable to Benfica for three good seasons, where he won the Portuguese League title in 2014, before returning to Chelsea.
Matic played a bigger role at Chelsea in his second spell, and was surprisingly allowed to leave for Manchester United in the summer of 2017, where he is developing further under former manager Mourinho.
Lukaku was a gamble of a signing for Chelsea in 2011, at a fee reportedly close to £20 million (S$ 36.6 million).
Once again, it was a familiar story of Chelsea not affording a budding young talent a run of games with the first-team, as Lukaku only made 10 appearances in a Chelsea jersey without scoring a single goal.
He then had successful one-season loan spells at West Bromwich Albion and Everton, where he netted 17 and 15 goals respectively.
Yet, he failed to make the grade at Chelsea and was sold off to Everton, becoming their first choice striker.
Lukaku was the top scorer in the 2014/15 Europa League, before he joined his current club Manchester United, as he continues to score goals on a regular basis.
Kevin De Bruyne
The jewel in Guardiola’s crown at Manchester City, Kevin De Bruyne was first discovered by Chelsea scouts, and the club signed him from Belgian side Genk in 2012.
But, De Bruyne's time in London was nothing short of a disaster, where he made just three appearances at Stamford Bridge, and was never truly given a legitimate opportunity by Mourinho.
And boy, has the Belgian proven his former manager wrong.
After steamrolling the Bundesliga with Werder Bremen and Wolfsburg, De Bruyne finally returned to the Premier League with Manchester City, where he is into his third season. He has developed into a very fine playmaker, a player some have even gone so far as to describe as the best midfielder in the world.