Fifa insists its Independent Disciplinary Committee will work to reach a decision on the biting allegations levelled at Luis Suarez "as soon as possible".
TV footage appeared to show the Liverpool star sink his teeth into Giorgio Chiellini's shoulder during Uruguay's 1-0 win over Italy in Natal on Tuesday.
Suarez was not punished by referee Marco Rodriguez during the match despite Chiellini pulling down his shirt to reveal what appeared to be bite marks on his shoulder.
But Fifa confirmed on Tuesday evening that it had opened disciplinary proceedings against Suarez and the Disciplinary Committee will meet after 2100 CET to discuss the case, using video evidence to reach their decision.
Uruguay face Colombia in the World Cup round of 16 in the Maracana on Saturday and in a press briefing at the stadium on Wednesday morning, Fifa's head of media Delia Fischer insisted the Disciplinary Committee is aware of the "urgency" of the case, "particularly as Uruguay are still in the competition".
Fischer refused to speculate on the possibility of a Uruguay appeal, but article 118 of Fifa's disciplinary code states there is no right of appeal against suspensions of less than three matches or up to two months.
Some have suggested that Suarez could receive a global ban which affects his availability for Liverpool, and Fifa says the "duration and scope" of any suspension is at the committee's discretion.
The committee also reserves the right to take past offences into consideration - Suarez was banned for seven games in November 2010 for biting PSV midfielder gand received a 10-game suspension in April 2013 for biting Chelsea defender Branislav Ivanovic.