Gerard Pique said La Liga's title race is Real Madrid's to lose after Barcelona were held to a goalless draw against Sevilla.
Barca's first slip-up since returning from the three-month lockdown hands Real the chance to regain top spot on Sunday.
After their emphatic 3-0 win over Valencia on Thursday, Zinedine Zidane's side will move level on points with the Catalans if they beat Real Sociedad and above them due to their superior record head-to-head.
"Seeing what we've done in the last two rounds, it's going to be very difficult to win this league," said a despondent Pique afterwards.
"From what I've seen, it's very hard to see Real Madrid dropping points."
Asked about Pique's pessimism, Barcelona coach Quique Setien said: "I think it comes from frustration. I am optimistic. I think it will be tough for anyone to take maximum points."
A valuable point for Sevilla, meanwhile, gives them a five-point cushion over Getafe in fifth, though they have played a game more.
Barca could have few complaints at the Ramon Sanchez Pizjuan.
They never really troubled Sevilla for any prolonged period and the closest Lionel Messi came to scoring the 700th goal of his career were a pair of free-kicks tipped over.
The sight of goalkeeper Marc-Andre ter Stegen jogging up for a late corner demonstrated how big a blow they considered dropping points to be.
Yet Real Sociedad are still in the hunt for Champions League qualification and will offer Madrid no guarantees on Sunday while games against Getafe, Athletic Bilbao and Villarreal mean there are still plenty of hurdles for Zidane's team to overcome.
Barcelona though would appear to have the tougher run-in, with Athletic Bilbao, Atletico Madrid, Villarreal and local rivals Espanyol coming up.
Messi was well-contained by Sevilla and it could be the Argentinian was feeling the effects of a third consecutive 90 minutes in nine days.
Setien chose not to rest his captain in either of two comfortable wins over Leganes or Real Mallorca.
Instead, Antoine Griezmann dropped to the bench, with Martin Braithwaite preferred in the front three alongside Messi and Luis Suarez, who made his first start since January after recovering from a knee injury.
Sevilla's Jules Kounde shot just wide of the post early on but Barcelona controlled the opening 30 minutes, even if chances were few and far between.
Messi's curled free-kick was headed off the line by Kounde and Braithwaite almost had a tap-in when Tomas Vaclik dropped the ball, but it was hacked away.
The half ended with a scuffle and Messi was at the heart of it, squaring up to and then pushing over Sevilla's centre back Diego Carlos. Messi was unhappy with Carlos' challenge on Suarez but escaped punishment.