Couto, 24, made 62 competitive appearances for Dortmund over the last two seasons, having first joined on loan from Manchester City in 2024 before completing a full transfer 12 months later.
However, for the most part, he has struggled to get past Julian Ryerson on the right of BVB’s defence, only playing 19 Bundesliga games last term and not completing 90 minutes since February.
Watch: Couto got his second Bundesliga goal with the last kick of last season