Gavi is 17 and will stay that way until the season ends (he turns 18 on August 5). He is still classed as a Juvenil player despite the fact his time in the youth academy has ended. Koeman called him up and he took his chance, showing Barcelona he is important in the first team. Now they need to revise his contract.
They are working on it, but meanwhile, the list of clubs who are interested in him is growing, and they are asking after him, directly or indirectly, through his agent Ivan de la Pena. In England Man City, Liverpool and Chelsea are interested, while Bayern are sniffing too.
His release clause at present is 50m euros, a very good price for a player who is already in Luis Enrique’s Spain team. His potential is huge and the player has no ceiling. He has the technique of a La Masia player with the fighting spirit more common elsewhere, making him a succulent proposition.
Barcelona know of the interest but are staying calm and know first hand that the player wants stay at Camp Nou. However they will have to make sure his renewal is taken care of soon to stop the tempting offers coming in.