How about playing Coutinho as the 3rd midfielder, following Rodgers' strategy (which he later seemed to abandon) of developing him into a Deco type rather than and out-and-out AM? Because I'm starting to hate him on the wing. If this works maybe we can go back to the "diamond" and have this super-attacking, but also pretty hard-working lineup:
------------------Can------------------
------Henderson-----Coutinho----
----------------Firmino----------------
--------Sturridge------Origi---------
With 2 defensively solid full-backs this might just work.