Barcelona will reportedly place Douglas, Adriano, Dani Alves, Thomas Vermaelen and Marc Bartra on the transfer list this summer.
The Spanish champions are expected to have a busy transfer window as Luis Enrique looks to freshen his squad for the 2016-17 campaign.
According to Sport, Enrique is prepared to allow as many as five first-team defenders to leave, with Douglas, who has hardly featured for the Catalan outfit, the first that will be placed up for sale.
Bartra, Vermaelen and Adriano have also all struggled for first-team football this season, and according to the same report will be allowed to leave if their valuations are met. Alves has also been linked with a move away, despite maintaining his position as the first-choice right-back this season.
Barcelona will lift the Spanish title once again if they win all three of their remaining La Liga fixtures this term.