Solskjaer has been praised for implementing a more attacking style of football since taking the reins at Old Trafford in December, but Van Gaal, sacked by United in 2016, said that is not the case.

"The coach after me [Mourinho] changed to park-the-bus tactics and played on the counter," Van Gaal told the BBC.

"Now there is another coach who parks the bus and plays on the counter. The main difference between Mourinho and Solskjaer is that Solskjaer is winning.

"The way Manchester United are playing now is not the way Ferguson played. It is defensive, counter-attacking football. If you like it, you like it. If you think it is more exciting than my boring attacking, OK. But it is not my truth.

"It is very important that Manchester United qualifies for the Champions League, as it was when I was manager. But they can also win the Champions League because they play a defensive system and it is very difficult to beat them, which, whether you like it or not, is the result of Mourinho's work."

Ole Gunnar Solskjaer has overseen a Man United revival since stepping in for Jose Mourinho. Getty

Like Mourinho, Van Gaal was also criticised for what some supporters branded boring football during his two years at the club.

It is something the Dutchman, 67, fiercely denies, while also claiming the FA Cup he won during his spell is his "greatest achievement" despite lifting league titles in Netherlands, Spain and Germany and winning the Champions League with Ajax in 1995.

"You say it was boring. Why was it boring?" said Van Gaal. "Maybe it was boring attacking, but that was because the opponent parked the bus. Then you have to play at a higher tempo, which is difficult.

"I have a philosophy. I was convinced of it and by winning trophies in four countries, I proved the philosophy worked.

"What I don't like is [Ed] Woodward contacting my successor, knowing in his mind he will replace me and he keeps his mouth shut for six months.

"Every Friday I had to go into press conferences and be asked what I thought about the rumours. What does that do to the authority of the coach?

"To win the FA Cup when, for six months, the media has a noose around my neck, is my biggest achievement."