Celta Vigo will force Barcelona to pay £15million (€18m) if they want 27-year-old Javi Galan this summer, with the left back highly coveted by Barca manager Xavi.
It is thought the Catalan giants will opt for Galan if they cannot negotiate a deal to get Marcos Alonso from Chelsea.
Barca are still confident they are favourites to sign Jules Kounde, ahead of the London club, as they seek defensive reinforcements before the start of the La Liga season.
And Mundo Deportivo report that while Celta do not wish to part with Galan, they would if the release clause is met - and Barca know this.