Gavi's injury is trending and I see a lot of sports media reporting about it. I know it is a big loss for Gavi and Barcelona, but Barcelona should not be affected by the injury of one of its important midfielders this season. Barcelona will have an equally good line up with Gavi or without him as long as De Jong, Pedri and Gundogan are fine, but if these three players are absent then I believe Barcelona are in trouble.
De Jong reportedly will return soon and will be available for the match against Rayo Vallecano. I'm happy with the news, but I hope Xavi doesn't insist on playing De Jong if he hasn't fully recovered and got a game. Pedri, Ilkay Gundogan and Fermin Lopez can be played as midfielders, but I think Xavi will call up several other midfielders from Barcelona B to cover the lack of players.
Gavi is a first-team player, so his absence will in any case affect the club. Barcelona cannot play the whole season with 11 players, they need rotation and when the main player drops out it affects all plans. That is why Barcelona is now looking for options to replace him (and by the way, as always, they are doing this in tight financial conditions).
Gavi is a young player and he can have the time to get back in the good form and play for his team later, but the problem with Gavi and Barcelona is Xavi was counting on this player, and Gavi is an important player for Xavi, and his team but now they can be the chance to buy another player and hope to see good performance from that alternative player.