Gerard Pique has apologised for his behaviour during Barcelona's Spanish Super Cup second leg against Athletic Bilbao at the Camp Nou but denied personally insulting the assistant referee.
Pique was sent off by referee Carlos Velasco Carballo during the second half of the 1-1 draw after TV pictures showed him angrily protesting to his assistant over an offside call.
Velasco Carballo's official report says that Pique used foul and abusive language when shouting at the assistant.
"In minute 55 the player  Pique Bernabeu, Gerard, was sent off for the following reason: shouting at an assistant referee, "I s--- on your f---ing mother," the report said.
Article 94 of the Spanish FA (RFEF)'s disciplinary code stipulates that "insulting, offending or approaching the referee, assistants, fourth official, directors or other sporting authorities in an intimidating manner will be punished with a suspension of four to 12 games."
However, Pique has said he did not use the language described in the report.
- Gerard Piqué (@3gerardpique) August 18, 2015
"I want to apologise as the attitude with which I protested to the linesman was not correct," he said in a message posted on Twitter. "It was a game with a lot of tension, when we had a lot on the line. However, in no moment did I use any type of insult towards his person."
Barcelona also published a statement on their official website that said the club had communicated Pique's version of events to the RFEF.
"Barcelona have presented arguments against the red card shown to Gerard Pique in the 58th minute of the game against Athletic Club in the second leg of the Spanish Super Cup," the statement read. "The argument put forward is that the player did not address the referee's assistant in the terms included by referee Velasco Carballo in his subsequent report."
Barca midfielder Ivan Rakitic defended his teammate, telling AS: "We are concerned as [Pique] is a very important player, but a sending off like that ... I don't know.
"He did not say it with bad intention. We were all nervous, all heated. He did not go especially at the linesman. If this was taken into account in all games, we would end up with seven or eight players sent off.
"We must learn from this. I hope he doesn't get many games [ban], because he is an important player. We are going to go on united, and when Gerard comes back, he will come back at his best."
Real Madrid defender Sergio Ramos saw a one-match ban extended to five games in 2013 when he was deemed to have used foul and abusive language towards referee Miguel Angel Ayza Gomez after being sent off during a Copa del Rey win over Celta Vigo.
Should Pique receive a four-match ban, he would miss Barca's opening La Liga game against Athletic on Sunday evening, as well as the Malaga at home on Aug. 28, Atletico Madrid away on Sept. 12 and Levante at home on Sept. 20.
Barca coach Luis Enrique faces a selection dilemma ahead of Sunday's game at San Mames, with Jeremy Mathieu also suspended, right-back Douglas injured, and left-backs Jordi Alba and Adriano both major doubts with fitness issues that have seen them miss recent games.