Dimitri Payet has revealed he first told West Ham boss Slaven Bilic last summer that he wanted a move and played his final games for the Londoners "without any pleasure".
French playmaker Payet was a star of Euro 2016 and forced a move away from the London Stadium in January after going on strike.
He joined Marseille for £25million, having become unhappy in London and fearing his talent was being stifled by Bilic's tactics.
"I didn't want to play my last roles in the Premier League," he said.
"Our way of approaching matches, the defensive system put in place, it didn't please me.
"It was difficult to express myself. You could say I was annoyed. I was going through games without taking any pleasure.
"I had contact with Marseille and notably (Marseille coach) Rudi Garcia, who has a philosophy I knew well. The choice was quick. If I waited six months, I'd lose six months."
In an interview with L'Equipe, Payet said a tipping point in his quest to leave was the home Premier League match against Hull on December 17, when Mark Noble's controversial penalty secured a 1-0 win.
"We won 1-0 and the opponents hit the posts four times," Payet said.
"In the dressing room everyone was happy, but the man of the match that day was the post.
"I said to myself that I wouldn't have any room for improvement. On the contrary, I was at risk of regressing. I needed another challenge."
He emphasised that his wife's wish to return to Marseille, where Payet played previously, was a factor in the decision to leave London.
But he also said West Ham should have been prepared to lose him.
"I warned them," Payet said. "I was going to do it and maybe they didn't take me seriously. I told them eye to eye that I would take the consequences of my actions.
"Slaven Bilic knew that I wanted to go. At the start of the season, when I left the Euros, we talked about it. The club closed the door. I respected this choice.
"But the situation worsened. In January I told him that I wanted to go to Marseille and nowhere else, demanding he pass the message to the directors.
"On the day he told me it was a definitive no, I told him I wouldn't play for West Ham again."
Payet, 29, became a hated figure during his stand-off and said the fans "hated me as much as they loved me".
West Ham co-owner David Sullivan said after Payet's exit that the club felt "sincere disappointment" in their former star player, and that he had hoped to keep him at the club and "make an example of him".