A 2-2 draw at home to Valencia on Saturday left Real Madrid's title challenge in pieces, Pepe conceded.
Real Madrid defender Pepe has accepted that the 2-2 draw with Valencia now makes winning the Liga title an unlikely goal.
Although Real finished level with Nuno Espirito Santo's men at full-time, things could have been even worse as they were forced to come from 2-0 down to salvage a point after first-half goals from Paco Alcacer and Javi Fuego.
Real seemed to be devoid of luck on the day, as they struck the frame of the goal three times before the break and even saw a Cristiano Ronaldo spot-kick saved by Diego Alves on the stroke of half-time.
Pepe began the fightback with a header early in the second period and former Valencia youngster Isco secured a point with delightful long-range effort six minutes from time, but the Portugal star acknowledged that clawing back Barcelona's four-point lead with two games left will be tough.
"We didn't start the match well, but we had a great second half," Pepe is quoted as saying by AS.
"La Liga is difficult now, but we must sweat for the jersey.
"It wasn't an easy match [for the officials], but the referee made things complicated."
Coach Carlo Ancelotti echoed Pepe's thoughts on the title race, though he is not giving up just yet.
"It is much more complicated now," he added. "But there are still two matches left and we must try to win both."