Fellaini has enjoyed a fine season at Old Trafford but his sending off at the KC stadium was reckless and unnecessary.
The Belgian stamped on Hull’s Paul McShane and will miss the start of next season as a result.
Van Gaal revealed he has spoken to Fellaini about the incident and expressed his disappointment in the player.
He said: “I could not see that from the bench, but I think it was a red card because the player [Paul McShane] needed seven minutes to stand up.
“He continued after that, so it was not so bad as everybody thought, but it is very stupid for him [Fellaini]. Next season he starts as a substitute [unavailable due to a three-match ban], because he has to sit in the stands suspended. That is very bad for a player and also bad for the manager and the team. It is worse for the individual player, because this season he also started in the stands.”
Fellaini will be desperately disappointed to end the season in such a way following what has been a fine campaign.
However, his suspension may turn out to be a blessing in disguise for United.
Fellaini isn’t the most technical player and United have sometimes reverted to negative tactics when he is on the pitch. Perhaps van Gaal will look to play with a more expressive style now that the 27-year-old will be forced to miss out.