It would not be farfetched to think of Thiago returning to Barcelona. He was destined to be Xavi's successor, but injuries took their toll on him and it was decided that the best thing for him would be to leave the Catalan side.
He went to Germany, to Bayern, and that is where he was at his best again. However, his time there looks to be coming to an end. This season he has lost importance at the Bavarian club and his departure could come sooner rather than later.
His destination is unknown, but 'Mundo Deportivo' are speculating on the possibility of him returning to Barca. Even though it looks like the Barca midfield is more than covered, the truth is that Arthur is really struggling to adapt to the club, something which Thiago would not have a problem with.