Jose Mourinho has been charged by the Football Association for claiming there is a "campaign" to influence referees' decisions against his Chelsea side.
Mourinho made his comments after his side were denied a penalty in the 1-1 draw with Southampton on 28 December.
Referee Anthony Taylor booked Cesc Fabregas for diving after going down in the box under Matt Targett's challenge.
Mourinho has been charged with misconduct and has until 18:00 GMT on 13 January to respond to the charge.
"It is alleged his remarks constitute improper conduct in that they allege and/or imply bias on the part of a referee or referees and/or bring the game into disrepute," read an FA statement.
Chelsea subsequently announced that Mourinho would not attend Friday's news conference ahead of the weekend meeting with Newcastle.
After the draw at St Mary's, the Stamford Bridge manager told BBC Sport: "The media, commentators, other managers are all doing it [putting pressure on referees]."
In his news conference later, he added: "There is a campaign against Chelsea. I don't know why there is this campaign and I do not care.
"Everybody knows it was a penalty."
Mourinho has also been issued with a formal warning for comments ahead of Chelsea's 2-0 win at Stoke on 22 December.
The Portuguese called on referee Neil Swarbrick to produce a strong performance at the Britannia Stadium.
"Having sought his observations on this matter, the FA has decided not to bring a disciplinary charge and instead issued him with a formal warning," added the statement.
"The FA prohibit participants from making any pre-match media comments, including comments of a positive nature concerning the appointed match officials for a particular fixture."