Celta Vigo legend Patxi Salinas says they must fight to keep hold of Gabri Veiga.
The young attacker is a top target for Arsenal and Manchester City.
Salinas said: "I am very sorry. We will have to enjoy him but with another shirt. It is clear that when a player hits this explosion and with that level of play, I am also convinced that he will be the next to debut with the Spanish team, it is very difficult for a club like Celta to be able to keep him.
"That's unless you make a brutal effort or the footballer, as (Oihan) Sancet did when renewing for eight seasons because he wanted to continue at Athletic, wants to stay.
"If I were the president of the club, I would fight with all my strength and until the last second. If I am the one who has to make the decision, I would not let him go just like that. I would fight even, if he signed for a big club, so that he could stay on loan for one or two years, because he is very young."