Barcelona boss Quique Setien has expressed his belief that there is an idea that VAR "is not being used well" after Real Madrid's controversial victory over Real Sociedad.
Madrid earned a 2-1 victory at the Anoeta on Sunday thanks to second-half goals from Sergio Ramos and Karim Benzema, but benefitted from a number of contentious refereeing decisions to move above Barca at the Liga summit.
Sociedad thought they had equalised when Adnan Januzaj fired past Thibaut Courtois from long distance, but the goal was ruled out for offside because Mikel Merino was deemed to be blocking the Madrid goalkeeper's view.
The home side's woes were compounded when Benzema appeared to control the ball with his arm before firing the winning goal in the 70th minute, with the Frenchman eventually cleared of handball after a VAR review pitchside.
Barca were held to a 0-0 draw away at Sevilla on Friday, and are now trailing their arch-rivals due to an inferior head-to-head record heading into the final eight matches of the season.
Ahead of a meeting with Athletic Club on Tuesday, Setien called for VAR to be used more effectively in order to ensure a level playing field.
"I'm focusing on us," the Barcelona manager told a pre-match press conference. "We have footballing problems, but I'm very happy with a lot of the things we're doing.
"We've won two and drawn one. We've scored six goals and we haven't conceded a single one. VAR is a tool we have that can make us better.
"But we must use it and have a clearer vision of reality. It is fair to ask why some actions are reviewed and others are not.
"It can lead to the idea that it is not being used well."
Setien went on to admit that Barca cannot afford any more slip-ups in pursuit of a third successive domestic crown.
"It's true that goal difference puts us below," he added. "But we still have the same amount of points. They [Real Madrid] can't make any mistakes either.
"Many leagues have been resolved in the last few games. Things are still the same.
"We're behind, but there are eight games left and we have the same idea of winning every game and being there until the last one.
"I knew we had to win almost everything, just like them."