The club is willing to let him go, but only if the new team includes a clause that allows Barcelona to buy him back in the future.
Stuttgart and Bayer Leverkusen have already shown interest in Darvich and have talked to Barcelona about the possibility of signing him. However, the transfer negotiations are still in the early stages.
Barcelona wants to keep an eye on Darvich's future and ensure he has a smooth transition to his new team.