Jordi Alba has apologised for making a middle finger gesture at a Real Sociedad fan during Barcelona's thrilling 4-2 win at Anoeta on Sunday.
Barca came from two goals down to record their first La Liga win in San Sebastian in 11 years, dating to 2007.
During the second half of the game, which saw the Catalan side extend their unbeaten run to 29 games in all competitions, left-back Alba became embroiled in a spat with one of the home supporters.
"I was caught, no?" he asked reporters when asked if he had stuck his middle finger up at the fan in question.
"If I offended anyone then I apologise. I'm like that on the pitch. They were saying all kind of things to me and I took it as part of the spectacle. I didn't mean to annoy anyone. If the person that offended me knew me, I am sure they would come to dinner with me."
La Real had raced into a two-goal lead with first-half efforts from Willian Jose and Juanmi as they looked to extend their unbeaten home record against Barca to eight La Liga games.
However, Paulinho scored before half-time to drag Barca back into the match and a brace from Luis Suarez and a Lionel Messi free kick completed the turnaround in the pouring Basque rain.
The three points restored Barca's nine-point lead over Atletico Madrid at the halfway stage of the campaign.
Valencia and Real Madrid, meanwhile, trail Ernesto Valverde's side by 11 and 19 points, respectively, although the latter do have a game in hand against Leganes.
"No, La Liga is still not in the bag, but the sensations are good," Alba said when it was suggested Barca have already wrapped up the title.
"We hope that we can keep going until the end of the season. Atletico are second and best-placed, but all of our rivals want to win the league and will give their all in the title race until the final day."
But Alba did suggest that Madrid, who were beaten by Villarreal on Saturday and are without a win in their last three league games, are getting away without too much criticism.
"If we were 19 points back from Real Madrid, they would kill us here [in the Catalan press]," he added. "We're more critical here, the press and the supporters. There [in Madrid], they cover it up more."