Barcelona defender Gerard Pique denied insulting the linesman during his side's Supercopa de Espana clash as he asked for forgiveness.

Pique, 28, was sent off early in the second half of the 1-1 draw against Athletic Bilbao at Camp Nou on Monday as Barca went down 5-1 on aggregate.

The Spaniard was accused of telling the assistant: "I s*** on your whore mother" as he was red-carded to end Barca's slim chances of a remarkable comeback.

With Barca having appealed the red card, Pique denied saying anything to the linesman.

"I want to ask for forgiveness because the attitude with which I protested to the linesman was not correct," he tweeted. "It was a match of high tension that was very important. However, not at any time did I use any type of insult to this person."

Pique could face a suspension of 4 to 12 games, with the decision expected Wednesday.