The FA has charged Diego Costa with misconduct after the Chelsea striker was sent off in Saturday's FA Cup defeat to Everton.
Costa, who has until Thursday to respond to the charge, was shown a second yellow in the 84th minute after reacting angrily to a tackle from Everton's Gareth Barry late in the second half.
Replays appeared to show the Spain international opening his mouth toward Barry's neck while the pair were tangled together, though Barry said he was not bitten.
"It is alleged his behaviour, after being shown a second yellow card in the game, amounted to improper conduct," an FA statement said.
The FA also warned that Costa has until Wednesday to explain a gesture directed to Everton fans at half-time.
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.
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 £32 million 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 semifinal 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.
Press Association contributed to this report.