QPR boss Mark Hughes believes managers are "losing faith in referees" after the 2-0 defeat by Manchester United.
Captain Shaun Derry was harshly sent off in the loss at Old Trafford for fouling Ashley Young.
QPR will appeal against referee Lee Mason's decision as Young was clearly offside before Derry brushed him.
Hughes said: "You should have confidence that referees will get key decisions right. Just lately a lot of managers have lost faith in them."
Derry's dismissal, when the game was goalless, reduced struggling QPR to 10 men for more than 75 minutes.
Wayne Rooney scored from the resulting penalty before Paul Scholes added the second goal to leave QPR battling for survival.
Even United manager Sir Alex Ferguson admitted Young was offside when he was fouled.
On Saturday, QPR's relegation rivals Wigan were furious after losing to two offside goals against Chelsea.
"You worry more about decisions going against you and it shouldn't be like that," added Hughes.
"You have to be 100% right to give the decisions. It is a difficult job. You have to be strong and really clear.
"At the moment people are guessing and hoping that they get it correct. That was the case today."
QPR chief executive Phil Beard was unimpressed with Young's reaction to the minimal contact from Derry, tweeting: "Difficult to take after watching numerous replays but Ashley Young could partner Tom Daley [the diver] at the Olympics."
Despite defeat, QPR ended the weekend in a slightly better position that they started it as fellow strugglers Bolton and Blackburn both suffered heavier defeats.
QPR remain in 17th spot - one point behind Bolton but level on points with Blackburn and Wigan, who are both in the relegation zone because of inferior goal differences.
Ferguson had some sympathy for former United player Hughes.
"Ashley was a yard offside and I understand why Mark is angry," said the United manager.
"There have been a lot of decisions like that in the last few weeks.
"It didn't help us at all. I was more confident before the man was sent off because the speed of our play and the movement was very good.
"After that we were just in a comfort zone."