Rafael Benitez had a "bad philosophy" and was never a good fit for Everton, according to Lucas Digne.
France international Digne left Everton in January, joining Aston Villa.
That move came after a falling-out with Benitez, with reports claiming that Digne – who did not feature for Everton after a 4-1 defeat to Liverpool on December 1 last year – had criticised the manager's conservative approach.
With Everton signing Vitaliy Mykolenko from Dynamo Kyiv, Digne was sold to Steven Gerrard's Villa for a reported £22million, less than a year after the left-back had signed a long-term contract with the Toffees, who he joined from Barcelona in 2018.
Yet less than a week after the switch to Villa had been finalised, Benitez was sacked after a defeat to Norwich City left Everton six points above the bottom three following a run of one win in 13 league games.
In an interview with L'Equpie, Digne did not hold back in his criticism of Benitez.
"I enjoyed three and a half years of happiness and love with the supporters," said the 28-year-old. "I had, and still have, a great relationship with them, with people at the club, my former team-mates.
"But I don't look back. Football is like that. One day everything's fine, and the next day, less so."
Regarding Benitez, Digne said: "The relationship we had was not good. It was complicated to be excluded from the squad for a month. It was an unprecedented situation in my career, but I had my family and my team-mates with me."
He said disagreement with Benitez concerned "the style of play, especially".
"I thought we had a team that could have a lot more possession. He asked me the question, I gave him my answer," Digne said. "I felt it legitimate to give him my feelings and those of the others in the dressing room. The group was unanimous. What followed proved me right, since he was fired because of poor results. I think he also had a bad philosophy. It didn't fit at Everton."
Benitez also suggested that Digne had informed him he did not wish to play for Everton, but this claim has also been refuted.
Digne said: "I never refused to play."
Matters have hardly improved for Everton under Frank Lampard, given they are just three points above the bottom three, albeit with games in hand on their rivals.