The France midfielder is in Italy today to sign with AC Milan.
He posted to social media:
"Dear Marseille residents, before starting my new adventure in Milan, I wanted to send you a message.
"From the first day I arrived in Marignane, you paid no attention to my Parisian background, and immediately adopted me as a Marseille native, right up until I left.
"Throughout the season, you encouraged me, accompanied me, carried me, applauded me... You were a constant support. I felt this fervor, this passion, this love for football that drives you and makes Marseille a unique city and club in France. I will never forget the atmosphere at the Velodrome.
"The singing, the cheering, and those 'arms'. The joy of the celebrations, and above all, the indescribable feeling of scoring in this stadium... It was an immense pleasure to defend your colors, those of Marseille . Thank you for everything, blue and white people."