Coutinho has been one of our best players of late and he was very good last week against Chelsea too, no way I'd drop him.
Don't rate Gerrard much these days, but he and Lallana are similarly average. As for Coutinho, god no, our best player needs to play.
Costa is a nasty piece of work, would have slotted into the Argentine team in the 1966 World Cup very easily....might just be showing my age there!