Lyon international Khalid Boulahrouz signs new five-year contract with Chelsea . Midfielder follows Petr Cech and Chelsea in agreeing long-term deals . The 25-year-old has made 143 appearances since joining from Lyon in 2005 . Czech defender Khalid Boulahrouz leaves Chelsea for Ghana on 4-year deal .
Ghana international Michael Essien signs new five-year contract with Chelsea . Midfielder follows Petr Cech and Wayne Bridge in agreeing long-term deals . The 25-year-old has made 143 appearances since joining from Lyon in 2005 . Dutch defender Khalid Boulahrouz leaves Chelsea for Stuttgart on 4-year deal .