Former Barcelona winger Luis Figo has called on Luis Enrique's side to prove their mettle after Sunday's loss to Valencia.
The Liga leaders' 2-1 defeat at Camp Nou means they are level on points with Atletico Madrid and one ahead of Real Madrid with five matches of the campaign to play.
With three defeats in a row in La Liga and having lost to Atleti in the Champions League quarter-finals, pressure is mounting on the Catalans to recapture the form which saw them go 39 games unbeaten this season.
Figo says that their slump is "not normal" and has challenged them to show sufficient mental strength to defend both their league and Copa del Rey crowns.
"I don't normally speak with the Catalan press but I'll make an exception," Figo said.
"What's happened to Barca isn't normal. To lose so many games in a row is not logical, but when you're in that situation, everything goes wrong.
"These are issues in the dynamic, it doesn't only depend on the quality of players. But the league is open and anything can happen.
"Things get tense and you have less of a margin for error, and that's when you see the character of teams."
Figo - who joined Madrid in an acrimonious transfer in 2000 - hit out at suggestions he has celebrated Barca's slump and insists any suggestion of bias has simply been created by the media.
"I don't celebrate when other teams lose, it doesn't bring me any happiness," said the former Portugal star. "I'm a sportsman, I have nothing against Barca - but you [the press] have something against me.
"I spent five amazing years there, I went for sporting and financial reasons and for a lack of recognition.
"Honestly, on Saturday I played golf, on Sunday I played golf, and my life does not depend on Barca or Madrid. I'm happier doing other things."