Newcastle United have announced that Fabricio Coloccini's contract has been terminated by mutual consent.
Coloccini, 34, signed for Newcastle from Deportivo La Coruna in 2008 and went on to make 248 league appearances for the club.
But following their relegation from the Premier League the defender will now return to his native Argentina to join San Lorenzo.
"GOODBYE FOR NOW": Fabricio Coloccini has written a letter to Newcastle United fans
- Newcastle United FC (@NUFC) July 5, 2016
Coloccini wrote in an open letter to the club's fans: "These were the reasons why I take this decision. I would not want to be in a situation where mentally, with so many years away from my children, I would not be able to be 100 per cent focussed here.
"But I am not going only for that reason. The mental strain of being eight years at this club and everything we have experienced, without being able to win a title, has also taken its toll.
"Without a doubt my playing years are coming to an end and I will continue with a football-related career after that. I will prepare myself for this and I will work towards being able to achieve as a coach what I was unable to fulfil as a player.
"Maybe one day I can return and contribute to winning a title for this club and the best fans in England.
"With mixed emotions of the joy of being able to return home but also the sadness of leaving the most important phase of my career, I'd like to say goodbye for now, forever grateful for the love you have given me and the opportunity to grow as a footballer and, most importantly, as a person."
Newcastle's managing director Lee Charnley said: "It is rare in football these days that a player gives such length of service to one club and I would like to thank Colo for his contribution to Newcastle United since he joined us before the start of the 2008-09 season.
"In the eight years he has been with us, Colo has become a firm friend and colleague to many players and staff, past and present, who I know will miss him. We wish him all the very best for his future career."