i don't think he was as bad as some people made it out to be. He tried to get some passes going and to go forward and help but imo that it is not his game and he is much better distributing from the back and in the midfield. Something that Poulsen also likes to do, so Tiago was asked to play a different role which isn't is his as hes not a box to box player.
He brings in something different than any of the other midfielders we have as he is the best passer. I think he should stay because of that as some games we will need to control the tempo more.