Fabricio Coloccini has written an open letter to Newcastle United fans.
The club today confirmed that the 34-year-old's contract had been "terminated by mutual consent" so he could join San Lorenzo in his native Argentina.
And Coloccini has written to supporters outlining his reasons for wanting to leave St James's Park.
Here, we publish his letter in full:
"I'm writing to you, my friends, and in general all you who have been part of this journey in this big club, that will always have a privileged place in my heart.
"To all the coaches, all the managers and the players I have been with and all the people that have accompanied us, in every stadium at home and away. To all the people that I have had the chance to have my picture taken with, and to all those people with their special song for me in the stadium who gave me their heart as well.
"You have adopted me here and made me feel welcome and so happy. You also opened the door to your house and your hearts when my loved ones were far away.
"This list of life friends could go on and on, but I can summarise it – this message is for all those people with black and white blood in their veins.
"It is at this point that I need to give a special mention to my adopted family.
"In reality, I always felt adopted by this club and by this beautiful city. But I would like to mention, in particular, the staff I have been honoured to work with over all of these years; the chefs, the physios, doctors, masseurs, kit men, domestic staff and cleaners, the security staff on reception, the media staff, the video analysts, the groundsmen, the laundry ladies, the secretaries and the other administrators.
"I'd like to make a special mention to those people, because from outside it's easy to just see the football match and the football player without realising the effort and the feeling, the emotion, care and the love that these people put into their work on a daily basis.
"These people adopted me and these people made it so much easier for me considering that I had a lot of my loved ones many miles away in my country. I will be forever grateful to them all.
"After all these years I understand that an open letter might not be the best way to say goodbye but I would rather put this in writing so that people can understand me better and so that things can be interpreted accurately.
"I spent about half my career at this club with very positive moments, but also with negative ones.
"Unfortunately, we couldn't lift a title for the club, which is a dream that I haven't been able to fulfil. And in this last year the club and players were not up to the standard of the competition, and for that reason we lost our Premier League status.
"Today I'm taking the decision of taking a step sideways, of leaving, for several reasons, none of which have anything to do with not wanting to play in the Championship.
"As I showed last time we lost our Premier League status, when even though I had a World Cup ahead of me, I still wanted to stay at the club.
"One of the main reasons is that after so many years of trying to achieve a title for the club and not being able to do it, it might be time to let other players arrive with the same drive, impetus and desire as I did years ago.
"For logical reasons, the mental strain of this is much more than the physical. For this reason, this is I think for me, the time to take a step sideways.
"Another very important reason is my children. They have been living in Argentina for a few years, they moved there when they were only little.
"But now I feel they need the presence of their father to help them find a healthy path and direction in life. Also to enjoy my family and my friends, because I left Argentina being only 17.
"Another point that you will undoubtedly understand because this is a city that lives and breathes football – I am 34-years-old now.
"I feel really well still physically and I am looking forward to carrying on playing football. This day had to arrive, when I had to return to mi gran querido San Lorenzo de Almagro, my home.
"They deserve the respect from me to come back still with hunger for glory and still physically able to make a contribution and today, thankfully, I have both.
"I am sure you'll understand this point because as a fan of a club I would always want a player to return at their best so that they can be enjoyed by the 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 focused 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."