Andres Iniesta admits Barcelona are doubting themselves after a difficult run of form was compounded with a Champions League exit.
Luis Enrique's men have won just one of their past five matches in all competitions and bowed out of Europe after a 2-0 loss to Atletico Madrid in the quarter-finals on Wednesday.
That completed a 3-2 aggregate victory for Atletico and ended Barca's title defence, leaving them to focus on La Liga and the Copa del Rey.
Iniesta, 31, said even Barca's star-studded line-up were beginning to question themselves.
"Difficult times like this always generate doubts but we have to turn the page and focus on what we have left," he said.
The star midfielder added: "We're not in very positive form.
"We have to find strength from somewhere because what we still have to play for is very nice too."
Barca were denied a late penalty after a Gabi handball was ruled to have been outside the area, despite replays suggesting it was inside.
But Iniesta refused to use that as an excuse, saying: "It's not a question of whether the referee was right or wrong. That would solve nothing.
"It is difficult to take in because we're out of such a nice tournament."