Doubts have persisted this season over the France attacker's place at Barca due to injury and discipline problems.
However, Setien has made it clear he's a fan of Dembele and is eager to work with the youngster.
He declared: "Ousmane Dembélé will be an important player in the squad because he is an extraordinary player.
"But he's been plagued by bad luck and missed a lot of continuity. But we hope he will help us a lot."