The 19-year-old midfield star is set to undergo surgery after suffering the serious knee injury during the first half of Spain’s win over Georgia.
Gavi also sustained meniscus damage in the non-contact incident, and is now likely to miss Euro 2024.
The tournament begins in Germany on 14 June with Spain confirming their place among the top seeds by topping qualifying Group A.
Gavi had featured heavily for Barcelona this season, with the Catalan club third in La Liga.
“The dressing room is like a funeral parlour,” said Spain coach Luis de la Fuente after a win over Georgia that he described as “the bitterest of my life”.
“It was an accident, it could have happened to anyone. “He’s [emotionally] broken, destroyed.
“This is the hardest moment I have experienced in football. We think we’re invulnerable but we’re fragile. I’m not thinking about the Euros or the Olympics or anything, only about Gavi’s health. These are uncontrollable situations. It’s a pity. The lad was in perfect condition to play. We always protect the players.”
The youngster has already played more than 100 times for Barcelona since breaking into the first team during the 2021/22 season.
He started all four of Spain’s matches at last year’s World Cup and has been a regular under De la Fuente, who replaced Luis Enrique after the conclusion of that tournament.
Teammate Ferran Torres celebrated Spain’s second goal in the 3-1 win against Georgia by retrieving Gavi’s shirt and holding it up to the crowd.
“Knowing what a warrior he is, and given the way he left the field, we know it must be serious,” Torres said.