Manchester United manager Louis van Gaal will contest a Football Association disrepute charge over comments he made after last month's FA Cup trip to Cambridge.

Van Gaal was charged by the governing body for remarks which "allege and/or imply bias on the part of the match referee and/or bringing the game into disrepute".

After the game at the Abbey Stadium on January 23, which ended 0-0, Van Gaal said: "You have seen the referee. It's always the same. Everywhere I have coached these games – and I have coached them also with other clubs – it's always the same."

Van Gaal had until Monday to respond to the charge, but has already decided he will fight it.

Speaking at a press conference, he said: "I am not angry, I am very disappointed. For nearly 30 years I have been a trainer, coach or manager and I have never been charged.

"Up to now I don't think I said something wrong. I said in our press conference the same phrases, because I know in advance that everything is in favour of the underdog. It is always like that.

"I said it in front of the game and after the game, only in the meaning that that is the general feeling of everybody – everybody for the underdog.

"I cannot imagine the FA has charged me, but it is like that."

Asked if he was contesting the charge, Van Gaal said: "Yes, of course. I never said anything wrong. I never say something about the referee, never."

United had been frustrated in the fourth-round clash, which was refereed by Chris Foy, but Van Gaal's comments did not cause particular consternation at the time.

The charge came on Wednesday to some general surprise following analysis by the FA.

Asked if he thought the FA could be making an example of him because he was the manager of United, Van Gaal said: "If I say that, then I am maybe (I am) rightly charged, so I don't say it."

United won their replay against League One Cambridge 3-0 at Old Trafford on Tuesday.

Van Gaal was speaking at the stadium shortly after attending a memorial service to commemorate the 57th anniversary of the Munich air disaster.

Eight United players – members of the club's famous 'Busby Babes' side – were among 23 people killed after a crash in the German city en route home from a European Cup match at Red Star Belgrade.

Van Gaal 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 in the history of this club. I think we have to remember that always."