The Football Association has warned Wayne Rooney over his future conduct for his remark to TV cameras after Manchester United's defeat by Chelsea.
United's England striker appeared to imply referee Martin Atkinson was biased in favour of the Blues during Sunday's game, which Chelsea won 1-0.
When leaving the Stamford Bridge pitch at full-time, Rooney mouthed the words "12 men" at a TV camera.
Atkinson had earlier booked Rooney for protesting about Chelsea's winner.
United boss Sir Alex Ferguson was also highly critical of Atkinson's decisions, but will not face any action from the FA.
Ferguson felt the free-kick from which John Terry scored should not have been awarded, and also felt Wes Brown was fouled as it went in.
"You lose faith in refereeing, that's the way the players see it," Ferguson said.
"The referee's position to make the decision [for the goal] was absolutely ridiculous. He can't see anything. It was a bad decision."
Atkinson awarded a foul when Darren Fletcher challenged Ashley Cole outside the box late on at Stamford Bridge, prompting protests from the United players, who felt the Scot had got the ball.
Ferguson also felt Didier Drogba pulled Brown's shirt as Terry's glanced header flew into the corner.