Mikel's strength on the ball and natural aggression make him an asset for both club and country. Mikel began his career with Plateau United in his homeland before spells with Ajax Cape town in South Africa and Norwegian side Lyn Oslo.

He fast became one of the most sought-after young players in Europe and in 2005 Manchester United beat a host of interested parties to his signature. But Mikel had other ideas, and despite appearing at a press conference in a United shirt, the midfielder claimed he had been pressured into the move and wanted to move to Chelsea instead. A legal dispute ensued but eventually the Chelsea deal was done, costing the Blues £16 million in a complex judgement which involved money being paid to both United and Lyn.

Jose Mourinho was delighted to get his man and Mikel started 24 games and scored twice in his first season, as well as winning the African Young Player of the Year Award for a second successive time. The midfielder's development continued in 2007-08 but questions continued to be raised about his temperament after he was sent-off against Manchester United and Everton, and he was an unused substitute in Chelsea's Champions League final defeat to United.

Michael Essien's injury absence allowed Mikel more playing time in 2008-09 and he seized the opportunity with a string of fine performances. He finished the season being nominated for the club's Player and Young Player of the Season awards.

He, too, suffered injury problems in 2009-10, but still started 21 Premier League games as Chelsea won the title.

For Nigeria, he was touted as a future superstar after a series of scintillating displays in the 2005 Under-20 World Youth Championships earned him the Silver Ball for second best player in the tournament, behind Lionel Messi. He played for the Super Eagles in the 2006, 2008 and 2010 African Nations Cup, and played seven games of the qualifying campaign for the 2010 World Cup.

But he missed the 2010 World Cup due to injury, saying he had to protect his long-term career rather that risk more serious problems by playing in South Africa. Strengths: Aggressive and fearless in the challenge, Mikel is not just an ankle-biter but has excellent distribution to boot.

Weaknesses: Poor discipline, Mikel has often been criticised for moments of petulance but at the age of 22, they can no longer be explained away as youthful over-exuberance.

Career High: Winning his first Premier League title with Chelsea in 2010.

Career Low: Being sent-off in the 2007 League Cup final against Arsenal in an incident that provoked ugly scenes. Also, missing out on the 2010 World Cup in Africa due to injury.

Style: Solid defensive midfielder, at best when deployed in the anchor role in front of the defence.

Quotes: "For the present and for the future he is a very important player for us. I hope that he stays at Chelsea for a lot of years. I would like that he puts in his great quality for the team." Carlo Ancelotti, July 2009.

Trivia: The scout who first recommended Mikel to Chelsea was Piet de Visser, who is also credited with bringing Brazilian superstars Romario and Ronaldo to Europe.