Dimitri Payet has said he was "bored" at West Ham United and needed to move to Marseille to avoid "going backwards."
Payet completed a controversial move back to Marseille in January after telling West Ham boss Slaven Bilic he no longer wanted to play for the Premier League club.
The France international, who enjoyed a stunning first season in England last term to help West Ham finish seventh, told L'Equipe a longer spell at the London club would have damaged his career.
"I didn't want to play the role of also-rans in the Premier League any more," Payet, who played under current Marseille boss Garcia at Lille, said. "I didn't like the way we approached matches, the defensive system put in place. With a 5-4-1 in front of our penalty area, I could have all the freedom in the world, but it made it difficult to express myself. You could say I was bored, yes.
"I went through matches without enjoying it. I had contact with OM and notably with Rudi Garcia, who has a philosophy I know well. The choice was quickly made. If I had waited six months, I would have wasted six months.
"With West Ham, at home to Hull, we won 1-0 and our opponents hit the woodwork four times. In the dressing room, everyone was happy, even though the man of the match that day had been the post. I said to myself I wouldn't have any room for improvement. On the contrary, I risked going backwards. I needed another challenge.
"I warned them. 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."
Payet was Marseille's marquee recruit in the winter transfer window as their new owner, American businessman Frank McCourt, attempts to build a squad capable of returning OM to the forefront of French and European football.
Garcia was appointed shortly after McCourt completed his takeover in October, and though the former Roma boss has taken the squad to the brink of the top five, OM's form has been inconsistent.
Speaking to media on Wednesday, Garcia claimed the squad he had inherited from his predecessor, Franck Passi, had been "made in spite of good sense," and complained he has "too many central defenders and there are positions where we don't have too much cover."
Passi, who was appointed interim coach of Lille last month, hit back at Garcia on Thursday.
"I'm a little surprised, but I'm not worried about it," Passi, who was assistant coach to Marcelo Bielsa at OM before eventually taking charge of the first team outright, said.
He pointed out 14 players had left and 10 had been brought in last summer, including Florian Thauvin, Bafetimbi Gomis and Clinton Njie.
"If we take into account just those three, they have scored 29 of OM's 40 goals," he added. "The recruitment was made to fit certain circumstances. There was a new owner coming in. We didn't have a lot of money. Those recruits have performed as such to allow OM to be where they are today."
Information from the Press Association was used in this report.