Barcelona manager Luis Enrique admits he is "worried" after the Spanish and European champions were beaten 4-0 by Athletic Bilbao in the Spanish Super Cup on Friday.
Mikel San Jose struck first at San Mames before Aritz Aduriz put Barca to the sword with a second-half hat-trick, meaning that the Catalans have now conceded eight goals in their last two matches.
"I'm concerned that we are letting in so many goals and it's an issue that we will correct," Enrique said. "We've gone from being the team to concede the least amount of goals to being a side which lets them in too easily.
"At the same time I congratulate Athletic. I've never played an easy game against Athletic in my life – never – not when I was a player not now as a coach. If you don't perform to the highest level, you will get punished."
Barca still have a chance to recover in the second leg of the contest at Camp Nou on Monday, and Enrique believes that his team still have the quality to bring themselves back into the game.
"It wouldn't be wouldn't be too presumptuous to think we can turn this around," he said. "We didn't give our best impression out there tonight, we didn't have much luck.
"The result is there and we cannot change it now. On Monday, with our fans behind us, we hope that we can get an early goal. If any team can respond to this result, it's us."