"I'm leaving because I feel the club no longer has the faith in me I need, and doesn't offer me the support to build something in the medium or long term," the Frenchman wrote in the letter published in the sports daily AS.
"I am a born winner and I was here to win trophies, but beyond this there are human beings, emotions, life and I have the feeling that these things have not been valued, that it has not been understood that this is also how the dynamic of a great club is maintained," he said.
"But everything I built on a daily basis, what I brought to the relationship with the players... has been forgotten."
"I'm leaving, but I'm not jumping ship and I'm not tired of coaching," he said.