Dimitri Payet claims he risked regressing if he had remained at West Ham, after railing against what he described as the defensive tactics adopted by Slaven Bilic this season.
The France international playmaker returned to Ligue 1 with Marseille in January, having agitated for a move away from London Stadium and been excluded from the first team late in his time with the Hammers.
The 29-year-old, who lit up the Premier League and helped the West Ham to finish seventh in his debut season, earning a place in the France team at Euro 2016, had claimed family reasons were behind his desire to leave.
But, speaking in an interview with L'Equipe, Payet has confirmed suspicions that West Ham's approach on the field, amid a poor start to the campaign, had also prompted him to consider the advances of the new owners at Stade Velodrome.
"I did not want to play late in my time in the Premier League," he said.
"We did not like the way we approached the matches, the defensive system that was put in place.
"With a 5-4-1 [formation]... I could have all the freedoms of the world, [but] it was complicated to express myself. You can say I was bothered, yes.
"I went through the matches without taking pleasure.
"I had this contact with OM and especially with [head coach] Rudi Garcia, who has a philosophy that I know well," he added, referring to their time together at Lille.
"The choice was quick. If I waited six months, I would lose six months."
Payet cited the fortuitous 1-0 victory at home to Hull in December, in which the visitors hit the woodwork three times before a controversial penalty secured the points for Bilic's men, as an example of his concerns.
"In the locker room everyone was happy, while the man of the match, that day, had been the post," he said.
"I thought I would not have any room for improvement. On the contrary, I risked regressing.
"Here, much is expected on me. There is a project with high objectives."