Van Gaal, 66, managed United for two seasons from 2014-16, winning the FA Cup in his final match at the helm. However, his teams never challenged for the Premier League title, while failing to guide them to the Champions League in his second season.

And Van Gaal now says that Man United under Mourinho play a "defensive" style of football, while adding he'd prefer to watch Manchester City, who beat the Red Devils on Sunday to extend their lead at the top of the table to 11 points their crosstown rivals.

"I would rather watch City play than United," Van Gaal told the Mirror. "You need quality in a squad and it's clear City have a better squad.

"If you ask me how did I do at United, I will say it was my best year ever, given the circumstances I was working under.

"We played football that was quite all right. But it's not football that is appreciated in England.

"And yet, right now, looking at United, I have to conclude Mourinho is not being criticised while it's far more boring football.

"What United produce now is defensive football. I always played attacking football. The proof is that the opposition were always parking the bus.

"They don't do that now because Jose Mourinho plays so defensive."

Mourinho was Van Gaal's assistant at Barcelona and the former Netherlands manager made it clear that he had no problems with the Portuguese coach. But he had less-kind words about Red Devils' CEO Ed Woodward, who sacked him the day after the FA Cup win.

"He [Mourinho] is not an awful man," Van Gaal said. "In fact, I think he is a sympathetic guy. He was my assistant at Barcelona.

"I worked with him and what Mourinho did [taking his job] is what often happens in football.'

"I have more problems with the CEO, Ed Woodward. He never discussed anything with me -- and you can talk about anything with me.

"With all my experience, I know the unwritten laws of football. A club has to prepare for the future.

"I can understand that and they should have approached me. Ed could talk to me but he did not.

"My wife had to find out [about Van Gaal's sacking] when she was in the lift with Woodward's family.

"They said something like: 'This is going to be awkward for Ed.' My wife had sussed them out ages ago. She warned me that something was going on.''