Louis van Gaal will deny a Football Association charge of bringing the game into dispute. The Manchester United manager said he was “not angry but disappointed” after being accused of implying bias on the part of the match referee, Chris Foy, after the goalless draw in the FA Cup at Cambridge United.

Van Gaal pointed to how this was the first time he had ever faced such a count from a football governing body in a 24-year managerial career. “I am not angry. I am very disappointed,” he said. “I am now for nearly 30 years a trainer-coach or manager and I have never been charged. And still, up to now, I don’t think that I said something wrong.

“I said already in our press conference the same phrases because I know in advance [of the tie] that everything is in favour of the underdog. You, as media, has confirmed that. It’s always like that.

“I said it in front of the game and I said it after the game, only in the meaning of the general feeling of everybody, everybody for the underdog. So I cannot imagine the FA has charged me. But, OK, it’s like that. Of course I will contest it. I never said anything wrong.”

Van Gaal also cited how he never makes comments generally about match officials. “You can confirm, as the media, that I never say anything about the referee, in all the matches I have played,” he said.

Following a sluggish display from his side against Cambridge in the fourth-round tie at the Abbey Stadium, Van Gaal said: “Every aspect of a match is against us. We have to come here, the pitch isn’t so good, that can influence that you can play in another style. The opponents always give a lot more than they normally give and defending is always easier than attacking. Then you have seen the referee - it’s always the same. Everywhere I have coached these games, and I have coached them with other clubs, it’s always the same.”

When it was put to the Dutchman that one of his predecessors, Sir Alex Ferguson, believed the FA could have an agenda against United due to the club’s status, Van Gaal said: “If I say that, then I am maybe rightly charged, so I don’t say it.”

The 63-year-old was speaking after a memorial service at Old Trafford to mark 57 years since the Munich air disaster in which 23 people died, including eight players and three United staff.

Of the ceremony the Dutchman said: “I represent the club nowadays as a manager and my group of players. They were also a group of players who brought a lot of joy to the people at that time. I think they have played a big part of the history of this club. I think we have to remember that always. There were men who were singing and I was impressed. I want to read in front of you what they said because I was impressed because of the big influence they still have now.

“These were the last sentences: ‘You are the strength and inspiration for those who play your roles today’ – that’s me and the players – ‘We look for flair and pace and passion, to play the game United’s way.’ I was happy I was there because of this and also the impression the people gave to me.

“I think we have made the right decision to be there, out of respect for the players and Matt Busby, and what they left. I think it was impressive for all the people and also me. It was 57 years ago and still the people are coming and still we remember and that doesn’t happen so often, so I think it’s good.”

When asked if his United play with the description read out in the memorial – “flair and pace and passion, to play the game United’s way” – Van Gaal concurred. “It’s not a question playing with wingers or three or four defenders,” he said. “It is a playing style that is attractive.”