Uefa has charged Chelsea players Didier Drogba and Jose Bosingwa for insulting the referee after their Champions League exit at the hands of Barcelona.
Uefa has also initiated disciplinary proceedings against Chelsea for the improper conduct of their players and the throwing of missiles by their fans.
Uefa has asked for a response by 29 May and will deal with the case on 17 June.
The Blues lost their semi-final after a series of controversial refereeing decisions by Tom Henning Ovrebo.
The Norwegian turned down a host of strong penalty appeals from Chelsea during their 1-1, second leg game at Stamford Bridge on 6 May that saw Barca go through on away goals.
Drogba and several team-mates surrounded Ovrebo after the final whistle to remonstrate with the Norwegian official over several of his decisions.
Drogba continued his verbal attack even after being cautioned, and had to be restrained as Ovrebo went down the tunnel.
Chelsea coach Guus Hiddink had said he hoped Uefa "might perfectly understand that the big apology of his was OK."
But a Uefa statement said: "The club are charged with the improper conduct of their players and the throwing of missiles by their supporters.
"Drogba and Bosingwa are accused of being in breach of the principles of sportsmanship by insulting the referee by making offensive comments."
Bosingwa is in trouble for comments he made to Portuguese television station RTP after the game.
"I don't know if he's a referee or a thief," said Bosingwa at the time. "I don't have any words to describe that man that was on the pitch."
He later also issued an apology, saying: "We were all very disappointed and frustrated after the game, but I regret describing the referee as a thief. Having had some time to reflect I would like to withdraw those comments."