The 25-year-old defender was dismissed after receiving two yellow cards from referee Alberto Undiano Mallenco, the first for obstructing a free-kick and the second for a foul on Carlos Vela, in a match that saw the leaders beaten for the first time in La Liga this season.

The Spain centre-half, speaking to journalists after the game, regretted the red card but did not appear to blame the official for his decision.

"They were two isolated instances where the referee decided to give a yellow card, and that's that," he told Marca.

"We have to accept it. I don't consider myself a dirty player at all, but I was given my marching orders."

However, Pique later took to Twitter to defend his disciplinary record.

"Season 2012/13: 14 games played, seven fouls committed, five yellow cards, one red," he wroteon the social networking site.

It was the sixth time Pique has been sent off in his career.

Despite the result against Sociedad, Barcelona remain top of the table with 55 points from 20 games.