Barcelona suffered a disappointing defeat in their Champions League clash with Shakhtar Donetsk, leaving their qualification hopes hanging in the balance.
The Ukrainian side took the lead in the first half and defended resolutely to secure a deserved victory, leaving Barcelona to rue their missed opportunities.
"We are in a bad moment. It's a mental issue. We are blocked," admitted Barcelona coach Xavi Hernandez. "We lost the ball a lot, we did not attack well, we did not defend that lateral centre well, and mistakes are costly."
Barcelona had a chance to seal their place in the knockout stages with a win, but they will now have to wait until their next two games to secure their qualification.
"We deserved to lose," Xavi acknowledged. "This is one of the worst games we've played since I arrived at Barca two seasons ago."
Barcelona will need to regroup and rediscover their form if they are to progress in the Champions League and salvage their season.