“It's with mixed emotions that I am writing this message," he posted on Twitter.
“To everyone at Chelsea Football Club. The owner Mr Abramovich who brought me here, to my teammates who helped me win so many trophies, to the staff who made my time here so easy and to all you fans who made me feel so special week in week out.
“It has been an incredible journey and it is with great sadness that I must say goodbye. I will miss you all and wish you the best of luck for the future."