FIFA has been formally informed of an appeal against Luis Suarez's ban for biting Italy's Giorgio Chiellini.
The Uruguay football federation will now have a further seven days to prepare the paperwork for the appeal.
FIFA head of media Delia Fischer told a news conference in Rio de Janeiro: "We have received a declaration that they are planning to appeal. They informed us of their intention to appeal yesterday evening.
"The reasons for the appeal must now be given in writing within a deadline of seven days after the three days has expired."
Suarez was banned from all football for four months, plus nine international matches, and fined 100,000 Swiss francs (just over £65,000) for biting Chiellini.
The Liverpool striker has left the World Cup in Brazil and returned to Uruguay.
On Friday, Uruguay coach Oscar Tabarez suggested the English media were to blame for the "excessive" sanction and announced he was standing down from his role on FIFA's Technical Study Group because he thought the World Cup record ban was too harsh.