Unfortunately for Blues supporters, those two are now undisputed world superstars.

De Bruyne has evolved into arguably the best midfielder on the planet since leaving Chelsea Credit: AFP

Nathan Ake stars for Man City and Holland Credit: Getty

But, before they reached their current elite level, they were once allowed to leave Stamford Bridge as underplayed, underachieving youngsters.

And they’re not the only two either.

We’ve taken a look at SIX players who could have been starring in West London, if they had not failed to make the grade at Chelsea before going on to become superstars elsewhere.

It’s enough to make you weep… if you’re a Blues fan that is.

NATHAN AKE

THE Dutch defender joined Chelsea’s youth ranks from Feyenoord in 2011, before moving to the senior squad a year later.

But Ake made just seven appearances for the Blues in the Premier League and was loaned out to Reading, Watford and Bournemouth.

Ake eventually found a permanent home on the south coast and became a star for the Cherries.

Bournemouth fought hard to keep Ake for three years – in which he played over 100 times in the Premier League.

But with Manchester United and City both knocking, the Cherries eventually cashed in to the tune of £40m following their relegation in the summer.

Now at the Etihad, Ake has helped Guardiola’s City to two Premier League title wins.

KEVIN DE BRUYNE

NOW quite possibly the best midfielder on the planet, it’s barely-believable De Bruyne was a Chelsea misfit.

Having signed from Belgian side Genk in 2011-12, the now-Manchester City star played just two Premier League games for the Blues.

On the periphery of the first-team squad, De Bruyne was loaned to Werder Bremen, before being sold to Wolfsburg for just £16.7m.

There, De Bruyne’s class shone through and his career took off, joining City for £55million in 2015.

The pass-master has won three Premier League trophies at City in easily the club’s greatest era.

MOHAMED SALAH

SALAH joined Chelsea from Basel in 2014 – but played just 13 times in the league, scoring twice.

In 2015 and 2016, the Egyptian was loaned out to Fiorentina and Roma – before joining the latter permanently, in a deal worth around £11m.

After just one season in the Italian capital, Liverpool were surprise suitors, bringing Salah back to the Premier League in a deal worth £36.7m.

In his first season at the Reds, Salah broke the Premier League record for most goals in a 38-game season.

In his second campaign, he won the Champions League.

And in his third, Salah inspired Liverpool to Premier League success.

Salah is now easily ranked as one of the world’s best forwards – and will always be the one who got away from Chelsea.

DECLAN RICE

THE England international and his family were all huge Blues and he must have thought he was well on his way of achieving his childhood dream of playing for them when he was signed to their academy.

But the midfielder was released by Chelsea aged 14 back in 2013.

The determined star was not to be deterred, and after a successful trial, he was quickly snapped up by West Ham.

Rice has not looked back since and has progressed through the ranks in East London and broke into their first-team at the end of the 2016-17 season.

He is now the stand-out performer for the Hammers on an almost weekly basis, and one of the first names on the team sheet for England.

Those displays caught the eye of several big boys, including Arsenal and Manchester United, but it is Chelsea who desperately want him to return.

NEMANJA MATIC

SIGNED from now-defunct Slovak side Kosice in 2009, Matic was tipped to become an attacking midfield superstar at the Blues.

The Serbian midfielder had played just twice in the Premier League and was loaned out to Vitesse in Holland.

But after two years – and a switch to a more defensive role – Matic was sold to Benfica as part of the 2011 deal that saw David Luiz arrive at Stamford Bridge.

But after starring at Benfica, Chelsea splashed out £21m – nearly 20 times what they initially bought him for – to re-sign him in 2014.

Matic would later join Man Utd in 2017 but has now reunited with Jose Mourinho at Roma.