Barca struggled in front of goal in the disappointing stalemate at the Camp Nou last weekend and face a tricky trip to Real Sociedad on Sunday.
Barcelona on Thursday said that Sevilla agreed to transfer the highly touted center back for a still-undisclosed sum.
The Catalan giants move two points ahead of Sevilla and nine clear of fifth-placed Real Betis, who have a game in hand, with four matches to play this season.
It was the type of statement Barcelona needed in a difficult rebuilding year following the departure of Lionel Messi and the collapse of its finances.
A deal that would see highly rated Gremio midfielder Arthur move to Barcelona next January is 90 per cent complete.