The fullback is currently playing on a season-long loan at Sporting, but Sport says he did everything he could to stay at the Nou Camp.
So much so, that when he was summoned to Barca's offices to sign contracts, Douglas appeared, but then turned on heels and rushed out. Those in attendance say the Brazilian was visibly shocked by Barca's insistence that he leave and refused to do so.
It was only after directors sent a lawyer after Douglas to insist he return that everything settled down and he agreed to put pen to paper.
Douglas joined Barca in 2014 on a five-year contract.