Michael Ballack
As Germany captain and a veteran of a World Cup final by the time of his move to Chelsea in 2006, Michael Ballack's capture on a free transfer from Bayern Munich was seen as something of a coup for Chelsea.
The central midfielder made an immediate impact at Stamford Bridge too, helping the club to the FA Cup and League Cup double in his debut season and reaching the Champions League final a year later.
A second FA Cup trophy followed in 2008-09 before Ballack captured the Premier League for the first time as part of the club's maiden double in 2009-10 - a campaign which proved to be his last with the club.
Ballack left Stamford Bridge having scored 25 goals in 166 appearances across all competitions, including 16 in 105 Premier League outings to help the club to five major honours.
