The 21-year-old whose Chelsea career is over before it began

Mourinho identified him as a major prospect, but injury has forced English defender Sam Hutchinson to retire

Chelsea's promising 21-year-old defender Sam Hutchinson has been forced to retire because of a chronic knee injury, depriving the club of one of the young talents they had marked out for a first-team future.

Hutchinson, who only turned 21 this month, has made four appearances for the first team and was first picked out by Jose Mourinho as one for the future, making his senior debut at the age of 18 against Everton in 2007. Hutchinson was also the captain of the Chelsea reserve team last season, which was severely curtailed by injury.

In response to The Independent's story, Chelsea last night brought forward the announcement of Hutchinson's retirement. The club have told the player that they want to keep him at the club and he is expected to be offered a role as a "player mentor", helping the development of young players from the academy.

Hutchinson joined Chelsea at the age of nine and can play at right-back or centre-back. He has captained England at Under-19s level and had a call-up for the England Under-21s squad but was yet to get his first cap.

Hutchinson has undergone a series of operations on his knee and has travelled to America to see specialists. He played two first-team games at the start of last season, in the 2-0 win over Fulham in the Premier League and the Carling Cup victory over Queen's Park Rangers. He succumbed to injury after that but returned at the end of the season to play in the 7-0 win against Stoke City.

Hutchinson's involvement at the club pre-dated the Frank Arnesen overhaul of the academy, under which large transfer fees were spent cherry-picking the best youngsters from academies all over Europe. Hutchinson was scouted in his hometown of Slough and Chelsea were eager that he make the grade as a player, so his retirement is a source of great sadness at the club.

He was rated highly by Carlo Ancelotti but the Italian has scarcely been able to select the player. He would eventually have also counted as one of the eight regulation "home-grown" players under the Premier League's new squad quota rules – particularly valuable for a club that does not have many players in that category.

Arguably Hutchinson's best moment in a Chelsea shirt came against Stoke last season when he crossed the ball for Frank Lampard's second goal. He also went on two pre-season tours to America – last year and with Mourinho in 2007 before the manager's final season at the club. His professional contract is due to expire in 2011.

Hutchinson followed in the footsteps of his father Eddie, who also played for Chelsea's youth team and went on to have a non-league career. In an interview in September, given after he played against QPR in the Carling Cup, Hutchinson said that it was his ambition to build a career at the club he has been since childhood.

He said: "Anyone who comes through the academy here, and is English in particular, is a bit special for the fans. Obviously JT [John Terry] is a world-class defender but I am still trying to make my trade. You can take bits from JT because he is so good, as is Riccy Carvalho and [Branislav] Ivanovic as well, and every bit of experience I get around them will help me and I can take a lot from everyone.

"I was scouted very young, so since I was about seven I played for Chelsea. [The QPR game] was a long time coming, so it was very exciting for my family and I had a load of tickets and got everyone down," said Hutchinson. "It was good for my mum, dad, two sisters and girlfriend. They have all been through it with me, and it was great for everyone."

Other careers cut short

Dean Ashton

Hailed as a long-term replacement for Alan Shearer, the forward suffered a broken ankle in training with England in August 2006. He struggled on before calling it a day last December.

Ben Collett

A central midfielder with Manchester United, his career was cut short when he had his leg broken by Middlesbrough's Gary Smith in 2003. Collett was forced to retire and, after legal proceedings, was awarded £4.5m in compensation.

Matt Jones

After impressing in the Leeds academy, the Welsh international made his bow for the club in January 1999. A year out with a knee ligament injury and back complaints led to his retirement in 2004.