The defender was dismissed by referee Darren England after studying slow-motion replays of a challenge on Omari Hutchinson, not initially penalised with a free-kick, following a VAR review.
While the forceful tackle did clearly hurt the Town man, Ruben Amorim was keen to stress afterwards that there was no malicious intent from his player, who is now going to be unavailable for Sunday's Emirates FA Cup fifth-round clash with Fulham.
Tickets for the Old Trafford game are still on sale.
Dorgu is also set to miss the Premier League games against Arsenal and Leicester City in March.