Rayo Vallecano coach Inigo Perez was furious after technical problems with the VAR meant a Barcelona penalty could not be checked during Sunday's 1-1 draw with the LaLiga champions.

Rayo rallied to earn a creditable point against Hansi Flick's side, who dropped points for the first time this season after back-to-back wins over Mallorca and Levante.

The Blaugrana went ahead through a 40th-minute spot-kick from Lamine Yamal, who had gone down under the challenge of Pep Chavarria on the right side of the area.

However, the decision was not reviewed due to issues with the VAR. Referee Mateo Busquets Ferrer informed both coaches before kick-off that the technology was not working, and after service briefly returned, it was reported that the connection was lost again in the 11th minute, meaning pitch-side reviews were not possible.

Perez reacted furiously on the sidelines and subsequently told DAZN that the match should have been postponed if the technology was not fully operational.

Perez later added: "It was a very complete game on our part; we had it drawn up in our heads.

"I was ashamed of my behaviour, it was the result of frustration. I have always supported the referees; I am a faithful defender of referees, even when they make errors. 

"What bothers me today is that players can't spend five minutes with VAR, five minutes without VAR... That influences the game lot. They have apologised to us. 

"I am bothered by the lack of efficiency. Maybe it's Rayo Vallecano's fault, I wouldn't be surprised if they made it sound like that. Cheating is a strong word, but it does mislead."

Hansi Flick, meanwhile, was unhappy with Barca's performance after they went through the entire second half without registering a shot on target, with Fran Perez getting Rayo's equaliser in the 67th minute.

He did reserve praise for recent signing Joan Garcia, however, after the goalkeeper made five saves to preserve a point for his team.

"We made a lot of mistakes; we can play much better. Rayo played fantastically. I'm not happy with my team today," Flick said.

"Rayo are a very intense team, but we had to control the game better. Joan Garcia played a fantastic game today, it was fantastic to see how he made his saves.

"He's very good with how he works with the ball. He's fast and didn't make any mistakes today. He is confident with the ball and without it. It was a good decision to sign him."

Barca host Valencia in their first game after the international break on September 14, having slipped two points behind Real Madrid and Athletic Bilbao.