Chelsea let Kylian Mbappe and £105m star slip through their fingers as new Cobham blow emerges

Chelsea have had many budding superstars in their ranks over the years

Chelsea have allowed some incredible talent to slip through their fingers as current high-profile transfer targets moved on before realising their true potential.

Yan Diomande has been the talk of the window this summer as Liverpool, Real Madrid and Paris Saint-Germain all make serious enquiries for the teenager. But just three years ago, the electric winger was on trial at Cobham with an opportunity to star for the Blues.

He eventually ended up at AS Frenzi after another trial at Scottish side Rangers, before moving to Leganes and signing for RB Leipzig last summer. His debut campaign in the Bundesliga captured global attention and he is now the subject of a transfer battle that is worth over £100million.

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Kylian Mbappe

Kylian Mbappe spent four days on trial at Chelsea as a 12-year-old back in 2011. The French superstar was brought to Cobham by Daniel Boga, one of the club's former scouts, who watched the teenager play for AS Bondy.

Boga told The Athletic that he was not blown away to begin with until he realised the youngster was playing two years above his age group. He explained: "I said, ‘Oh, that makes a big difference. If he’s good at under-14, that means in his own age group he will be something else.'"

He added: "When he has the ball… amazing. He pushes the ball and you can’t see him anymore. You could see that he had something special."

Unfortunately, the Blues declined to give Mbappe a deal after his trial and he would end up at Monaco as a 16-year-old. Paris Saint-Germain came calling next, and he won the World Cup in 2018 at just 19 years old.

Mbappe now shines for France and Real Madrid, with 376 goals and 140 assists across his entire career so far.

Declan Rice

Declan Rice had made his way through Chelsea's academy and was released as a 14-year-old in 2014. Former youth team-mate Dan Kemp admitted that the midfielder's exit came as a shock to everyone, telling talkSPORT: "It was really upsetting, but also the massive thing was how much of a shock it was.

"None of us saw it coming. Even at that age, he was such a good player. It was such a massive shock to see him go because I never thought for one minute he’d be released. I always thought he was going to get another contract because it didn’t even cross my mind that he would get released. It was tough.

"To this day, I couldn’t really think of a reason why they would release him. I suppose they had their individual reasons, which we’ll probably never, ever know. All I could do as a mate was be there and support him. I knew he’d be on to bigger and better things and that he’d have the resilience to bounce back."

Rice developed a close bond with Kemp and current Manchester United star Mason Mount, who spent six years at Stamford Bridge. The former Chelsea academy star began his career at West Ham, spending eight seasons there and becoming the club captain.

He won the Conference League in his final campaign and moved to Chelsea's city rivals Arsenal for an initial £100m, rising to £105m with add-ons.

Jamal Musiala

Jamal Musiala spent eight years in the Chelsea academy and was already showing signs of becoming a star at just eight years old. Blues scout Graham Castle was the first one to spot Musiala's skill and convinced his family to join the west London outfit.

He said: "I sold it to him to come up and have a look at our facilities and our coaching. When he got there, our coaching was levels above other places. It all fitted into place.

"Because it was towards the end of that season, our under-8s were already established. He went straight into a friendly game with Blackburn Rovers. From that, they took him on. They could see his ability. He was going around players for fun."

In 2019, the attacking midfielder would leave England and join Bayern Munich in Germany at just 16 years old. He spent time in the reserves before making his debut at 17 and finding the net, becoming the club's youngest ever goalscorer.

Since then, the now-23-year-old has won six Bundesliga titles, the Champions League and the FIFA Club World Cup. Musiala has also earned 46 caps for Germany and scored 10 goals, as he snubbed his English heritage.

Rayan Cherki

Rayan Cherki's Chelsea story is similar to that of the other French star on this list. He arrived at Cobham as a 12-year-old in 2015 and was "miles better than anyone else", according to ex-Blues youth star Miles Leaburn.

Cherki was still on the books at Lyon at the time, with the Ligue 1 outfit unaware of his presence in the capital for a trial. Leaburn told The Sun: "He came over from France and was rainbow-flicking guys in training.

"I was thinking, ‘Oh my God, this is incredible.’ He honestly rejected playing for Chelsea because he probably found it too easy. He was miles better than anyone else — absolute quality. That was one of the standout moments of the eight years or so I spent at Chelsea."

The 22-year-old winger would go on to make 185 appearances in France and make 75 goal contributions before moving to Manchester City for around £34m. Cherki has 27 goal contributions to his name at Manchester and got one over his former trialist club by winning the FA Cup final against them in May.