Wigan chairman Dave Whelan has claimed some referees "seem to be afraid of applying the law to Manchester United" after Wayne Rooney escaped a ban for his elbow on James McCarthy.
Referee Mark Clattenburg awarded a free-kick to Wigan following the incident, which Wigan boss Roberto Martinez felt "quite clearly" warranted a red card.
Although Clattenburg would have had to have admitted he did not see the incident, many had expected that Rooney would be punished retrospectively, and the Daily Telegraph reports that United "were so resigned to Wayne Rooney being charged ... they had explored possible loopholes to spare the 25 year-old from a ban".
Whelan, whose side were beaten 4-0 at the DW Stadium, said he felt Rooney's escape was unjustifiable.
"I cannot understand how the FA can say there will be no further action," he told the Daily Telegraph. "Manchester United is a great club and Fergie is just simply the best manager, but it is the referees who seem to be afraid of applying the law to United and I don't know why.
"Man United get treated a little bit differently to the rest of the football clubs. I wish they would treat Wigan like that. I wish we could get away with certain things that Man United get away with.
"Mark Clattenburg is usually a very good referee. I could not believe that he [Rooney] was not sent off. Had it been one of our players, he would have walked.
"Rooney was only ten yards from the referee and it was a deliberate elbow. It was the swipe of an elbow right across the head and a clear sending-off offence."
He added in The Sun: "Something is wrong when a top international like Rooney is seen doing something like this, as clear as day, and is allowed to get away without being punished.
"If it was any other club or player, you can bet your life he would have been sent off, but officials seem intimidated by the words 'Rooney' and 'United'. Manchester United are allowed to get away with things the rest of us get pulled up for, and you can't have one set of rules for one club and another for the rest.
"I don't care what the FA say about the matter being dealt with at the time by us getting a free-kick. They, and everyone else in football, know justice isn't being served here.
"The FA will be delighted they can hide behind their rules and let Rooney off, as they are frightened of taking sanctions against him and his club."
In the wake of the news that Rooney had escaped a ban on Monday, Professional Game Match Officials general manager Mike Riley defended Clattenburg.
"Mark took the correct course of action with this incident," he said. "Match officials are trained to prioritise following the ball, as that's where the greater majority of incidents are going to take place. However, we also do a lot of work around the area of peripheral vision to be aware of anything that might potentially happen off the ball.
"In this incident Mark was following play but caught sight of two players coming together and he awarded a free-kick because he believed one player had impeded the other.
"We should be clear that Mark did nothing wrong in officiating this incident as he acted on what he saw on the pitch.''