Louis van Gaal was unable to disagree with the red card given to Angel Di Maria on Monday night.
The Manchester United winger was sent off in the 77th minute of his side's 2-1 FA Cup quarter-final loss to Arsenal at Old Trafford for an altercation with referee Michael Oliver.
Di Maria was initially booked for diving before grabbing the back of Oliver's shirt in protest which prompted the match official to brandish a red card.
Of the decision against the former Real Madrid ace, van Gaal said: "In Spain he knows that he doesn't touch the referee, but that is also in his emotion.
"I've already spoken with him, he knows my opinion but also I have to see on the video. I think he's touched the referee and that's forbidden in every country, so he has no excuses.
"You never have to receive a red card if you control your emotions. The ref is the boss on the pitch and not Di Maria - he decides and you have to adapt to the referee and not the other way round."
