Uruguay's Luis Suarez says he lost his balance and did not bite Italy's Giorgio Chiellini at the World Cup.
Football's world governing body Fifa banned Suarez, 27, for four months and nine international matches for biting Chiellini in a group match on Tuesday.
Uruguay have told Fifa they intend to appeal against the decision.
"I lost my balance, making my body unstable and falling on top of my opponent," wrote Suarez in his defence to Fifa.
"At that moment I hit my face against the player leaving a small bruise on my cheek and a strong pain in my teeth."
In a document seen by Associated Press, the Liverpool striker added: "In no way it happened how you have described, as a bite or intent to bite."
However, a seven-man Fifa panel concluded that the bite was "deliberate, intentional and without provocation".
In its reasoning for the severity of the ban, Fifa added: "At no time did the player show any kind of remorse or admit to any violation of Fifa rules and therefore showed no awareness of having committed any infraction."