Chelsea striker Diego Costa has been charged with improper conduct by the Football Association following his red card in Saturday's FA Cup loss at Everton.
Television replays showed Costa nuzzling his mouth into Gareth Barry's neck, but the Everton midfielder insisted the Spain international had not bitten him.
Costa was sent off by referee Michael Oliver for two yellow cards in the FA Cup quarter-final defeat at Goodison Park.
A statement from the FA read: "Diego Costa has been charged in relation to Chelsea's FA Cup sixth round fixture against Everton on Saturday, March 12, 2016.
"It is alleged his behavior, after being shown a second yellow card in the game, amounted to improper conduct.
"He has until 6pm on March 17, 2016 to respond to the charge.
"Meanwhile, the Chelsea striker has until Wednesday (March 16, 2016) to provide his observations to the FA in relation to an alleged gesture he made towards Everton supporters while leaving the pitch at half-time."
The Chelsea front man has until Wednesday at 6pm to respond over the alleged gesture and until Thursday at 6pm to respond to the improper conduct charge, which followed his reaction to his dismissal.
His automatic one-match ban for his red card, which rules him out of Saturday's Premier League clash with West Ham, could be extended if the charge is proven and if he is also sanctioned for the alleged gesture.
Costa was dismissed in the 84th minute for a second bookable offence - his first red card as a Chelsea player - after grappling with Barry, but the England international insisted he had not been bitten by the striker.
Barry was sent off three minutes later for a second yellow card and will miss Everton's game with Arsenal on Saturday.
Chelsea boss Guus Hiddink, who said his player had been "chased" during the game, later joked that he and Costa should go together to watch the film "Anger Management" after a catalogue of incidents since his £32million ($45.7M) arrival at Stamford Bridge during the summer of 2014.
Costa is no stranger to controversy and had collected his 10th Chelsea yellow card of the season before seeing red.
He has twice been handed three-match retrospective bans by the FA. The first came after he was adjudged to have deliberately trodden on the ankle of Liverpool's Emre Can during a Capital One Cup semi-final in January 2015.
And the second three-match suspension followed an altercation with Laurent Koscielny in a Premier League defeat of Arsenal last September.
Costa is in his second season at Chelsea and is again reportedly agitating for a return to Atletico Madrid.
