Chelsea Football Club can confirm Michael Ballack will be leaving the club upon the expiration of his contract at the end of this month.

The midfielder has spent four years at Chelsea, and all at the club would like to place on record our thanks for his service and wish him luck for the future.

Having arrived at Stamford Bridge in the summer of 2006 as a free agent, Michael leaves us in the same manner after making 167 appearances (27 as substitute) and scoring 26 goals.

It was from Bayern Munich in his native Germany that he joined Chelsea, another star name to join Andriy Shevchenko at Stamford Bridge, though it was Ballack who would settle more comfortably to life in England.

Although he never managed to sustain the pre-Chelsea record of a goal every two games or so, his strong character, professionalism and will to win made him a popular character on and off the pitch - in a first season of acclimatisation he made key contributions at big moments, notably in the Carling Cup Final and the FA Cup semi, though ankle injury would keep him from the Final.

It was not until December of his second season he would feature again, but he hit the ground running and even took the captaincy with others either injured, suspended or at the 2008 African Nations. At this time Ballack scored important goals to haul us back into the title race, and smashed a penalty past Manchester United to bring us almost level with the eventual champions.

The second Champions League Final defeat of his career followed before an excellent Euro 2008, and he returned hopeful of a strong campaign with Chelsea, though another injury, this time to his feet, kept him out for a number of weeks during 2008/09 before a return to form and fitness under Guus Hiddink that helped secure the FA Cup.

Under Carlo Ancelotti he fitted in well to the midfield but was never an automatic selection, though early injury to Michael Essien provided less competition, before John Mikel Obi was ruled out for the final month of the season.

It was sad that on the day Ballack became the first German to win the Double in England, he was forced off in the Cup Final with ankle ligament damage that would force a withdrawal from the World Cup.

Michael will remain at Cobham for treatment until his injury is healed, but he will become a free agent as of July 1.