Nottingham Forest are considering whether to lodge an official complaint with the Professional Game Match Officials Limited (PGMOL) over the performance of the refereeing team
Forest boss Steve Cooper said he needed to "bite his tongue" over what he really felt about referee Stuart Attwell and his colleagues.
However, it is understood Forest officials left Old Trafford seething over various decisions they felt were pivotal in deciding the game's outcome.
After Saturday's game, which Forest led 2-0 after four minutes, Cooper said: "In games like this you need things to be how they should. I am not going to talk too much as I don't want to get into trouble but I was surprised how quickly the decisions were made.
I hope they do, managers and clubs inc us have to start calling it out more and getting it into the public domain. It’s got worse since Webb took over and Attwell should not officiate another Rag game