Barcelona left-back Jordi Alba has said that he could see that teammate Lionel Messi's strike against Valencia had crossed the line from "the middle of the pitch".
Messi was denied an equaliser by referee Ignacio Iglesias in Sunday's 1-1 draw with their La Liga opponents, after Rodrigo had given the hosts the lead after an hour.
The Argentine's strike from the edge of the area was fumbled by Valencia goalkeeper Neto, before the stopper tipped the ball back out after it had crossed the line.
"It was a mistake by the referee," Alba told Marca. "Even from the middle of the pitch I could see it.
"At the break we saw the replay and it is clear, these plays can't be missed.
"[Video technology] is just another form of technology that will help football. They will see plays like this and fix the problem."
Spanish international Alba netted Barca's equaliser after 82 minutes following an assist by Messi.