Louis van Gaal believes there was a “directed, organised” attempt from former Manchester United players to get him sacked.
Van Gaal was removed from his role as United manager in summer 2016, just two years into a three-year contract.
He was removed almost immediately after winning the FA Cup, with Jose Mourinho installed as his replacement.
In an interview with the Daily Mirror, the Dutchman says that he turned down the chance to manage Belgium so United would have to continue paying out the contract they terminated a year early.
“It would have been really great if I had become Belgium national coach,” said Van Gaal. “But I was so resentful and vindictive that I let that job go by.
“It was stupid, really, because the sporting value should always come in the first place.
“That should have been the most important thing. But that’s how I looked at things.
“It was not about money. It was all about the act of revenge. I went for my instinct, not the rational. I just have to live with that. I’ve been a really successful manager, so I don’t want to slag the world of football down. I have had a lot of good times.’’
“But the way Manchester United have treated me was terrible. They have been mean and low.
“The former players of United started to have a go, saying that I was giving the fans boring football. That struck me. It was directed, organised.
“After a while I started to think I’m losing my authority this way towards the players. So I had to make concessions in my approach of the players.
“That was tough, because I’ve always had my own way of coaching.’’