Barcelona will appeal against the VAR decision which saw Clement Lenglet sent off as they dropped their first points of the new La Liga season, held to a 2-2 draw by Catalan rivals Girona at Camp Nou on Sunday.
Lenglet was dismissed for "elbowing an opponent in the face when competing for the ball," according to referee Gil Manzano's report, but Barca feel that video footage proves it was not intentional.
Coach Ernesto Valverde argued that it "wasn't an act of aggression" on the defender's part and the club confirmed on Monday they will fight the decision, with the league due to discuss the issue on Tuesday.
Barca took an early lead through Lionel Messi but the game swung in the 35th minute when Lenglet, making his first league start following a €36 million summer switch from Sevilla, was dismissed for elbowing Pere Pons after intercepting the ball.
Uruguayan striker Cristhian Stuani scored either side of half-time to move Girona ahead but Gerard Pique equalised after the hour mark to earn the home side a point and maintain their unbeaten start to the campaign.
"The red card conditioned the game and we were unfortunate to concede at the end of the first half," Barca coach Valverde said in his post game news conference.
"The sending-off changed things a lot, we weren't able to come back [and win]. I've not seen it back on television. There's a coming together, of course, and it seems [Lenglet's] elbow has caught him.
"It must be the first red card in which the player who's on the end of the foul has apologised as Pons did to Lenglet. I suppose justice was done with VAR but I have the feeling that it's not a red card.
"It's possible there's an impact. I don't think it was an act of aggression, though, not at all. It's a foul by [Pons]."
Girona midfielder Pons collaborated Valverde's version of events, confirming that he said sorry to Lenglet and admitting he thought he was the player who had committed the foul at first.
"I did apologise to [Lenglet]," Pons said. "I didn't notice the contact from the elbow and I offered my hand to him because I thought it was a foul by me at first.
"I don't know if it was an act of aggression. We both went in 100 percent, we both caught each other. In the end, it was VAR that made the decision. I don't know it's a red card or not."
Barca midfielder Sergio Busquets was also perplexed by the verdict, questioning the use of VAR to reach the decision.
"Maybe there's contact, you can see that in the images, but the ball's on the ground and the movement Clement makes is a natural one," he told reporters after the game.
"It's not an act of aggression, he wasn't looking to do that. Even the Girona player apologised because he made the foul. VAR has to be used in the correct way and with consistent criteria.
"Until the red card, things were going well for us. After that, with one man less, it's harder, especially when we go behind. We tried, we got level again and we looked for the win... but it was tough with one less. We made a huge effort physically.
"It's a different game [with 10], we were good 11 against 11, we could have scored more goals. But going down to 10 left us up against it. We all like to play well and win, above all to win, so we will try to improve."
Barca, who are level with Real Madrid at the top of La Liga with 13 points from five games, travel to Leganes in the league on Wednesday and then host Athletic Bilbao at Camp Nou on Saturday.