The Argentinian's shot after 30 minutes of the first half was fumbled by Valencia goalkeeper Neto and TV replays showed the ball clearly crossed the line.

But without the option of referring to a TV official to check replays, referee Ignacio Iglesias did not award the goal at the Mestalla.

Barcelona manager Ernesto Valverde hailed the valuable point his side were able to secure on the day, but couldn't ignore the need for VAR technology after the match.

"We would have liked to get the three points but we are happy with how we played," Valverde said. "Their goal knocked us a little bit. But we showed courage throughout the match. We were able to get the equaliser and kept pushing for the second. It was a game with a lot of pressure, it's a good point.

"We can all agree that in these type of clear situations, when it's clear the ball has gone over the line, that [help is needed for referees]. We're not talking about re-refereeing the games, but we're still getting moments where the ball goes over line and it's not spotted and we can all see the evidence. But it also went in our favour against Malaga, when the ball went out of play before a goal that we scored...

"The Messi goal was clear and then we go behind. The important thing is we didn't lose our focus against a really strong opponent. Both teams were true to their style. They wanted to counter-attack quickly, in the first half we dominated, we didn't give much away. It was a good game, with a controversial moment which luckily didn't knock our focus.

"In the second half, they started a little better and got the goal, but after that we tried to take steps forward. We struggled a little with the space behind us but got the equaliser and went after the winner.

"It doesn't matter to us what people say [about how we play]. We now that we want to dominate a game and boss the possession. There are times when you're more fortunate than others. Our idea is to always be in control.

"Valencia are candidates for the title, they're showing that. We've seen the potential they have."

Jordi Alba scored Barca's equaliser in the 82nd minute, from an inch-perfect lob from Messi outside of the area. He did not play down the importance of the unrecognised goal.

"It was a monumental error by the referee. Even I could see it was in from the middle of the pitch," Alba said.

"We saw the replay at half-time and it's clear. It's so clear. There can be a foul and it can be interpreted one way or another, but these moments have to be seen. [VAR] is something which will help football [in Spain] and will stop moments like this happening.

"We had control of the game but after they got the goal they could have caught us out on the counter-attack. It's not easy to play here, Valencia are doing really well this season.

"The table shows that they can win the league, they're one of the candidates. There's a long way to go, but they're second for a reason."

Barca midfielder Sergio Busquets added: "There will be a lot of things that VAR can't clear up, but I hope that they can help with things likes today. It's an evolution which we need. It's something we need. And not just for this goal.

"La Liga has the best players in the world. It's the best league in the world and it deserves the best technology. The goal was over the line, but neither the referee nor the assistant saw it.

"It was a point against a difficult rival, but we deserved to win. We gave everything we could but in the end we haven't got the three points."