Southampton won 3-1 at Stamford Bridge on Saturday as the Blues slumped to their fourth defeat in eight matches to leave them 16th in the Premier League, their worst start to a top-flight season since 1978.
Mourinho received the backing of the Chelsea board on Monday but he must now answer an FA charge in relation to his comments about referee Robert Madley after the home defeat to the Saints.
The Blues boss was unhappy with Madley’s decision not to award a penalty when, with the scores at 1-1, striker Radamel Falcao was upended by Southampton goalkeeper Maarten Stekelenburg.
“It is alleged his [Mourinho’s] remarks constitute improper conduct in that they allege and/or imply bias on the part of a match official or match officials and/or bring the game into disrepute,” read a statement on the FA’s official website.
“He has until 6pm on Thursday to respond to the charge.”
Speaking after the game at Stamford Bridge, Mourinho said: “When everything goes against you, you need these decisions.
“One thing teams are not afraid of is to make penalties against us because they make them all the time and the referees they never give.
“It is a big confidence they feel because they are not afraid to be aggressive in the box.
“I tell my players to be careful in the box. These opponents know that they don’t have to feel that pressure.”
Mourinho was similarly unimpressed with the decision not to award his side a penalty in their 2-1 home defeat to Crystal Palace on August 29 and claimed last season there was a conspiracy against Chelsea.
“That’s a clear campaign. People, pundits, commentators, coaches from other teams – they react with Chelsea in a way they don’t react to other teams,” he said in December 2014 after they drew 1-1 at Southampton.
“They put lots of pressure on the referee and the referee makes a mistake.” — Sky Sports