Yeah, I was thinking along the same lines. Since we only have 2 CMs in decent form (Gerrard and Hendo), then it might make sense to adjust the system. Lucas was a waste of space against Arsenal, unfortunately, and the fact that Allen didn't even feature tells you everything.
I would do something like this:
(4-4-2):
---------Suarez---Studge-----
Enrique------------------Downing
----------Gerrard--Hendo---------
Johnson------------------Wisdom
----------Agger----Carra---------
---------------Reina---------------
I'd give Wisdom a break and go with this.....
------------------Reina-----------------------
Johnson-----Skrtel-----Agger--------Enrique
Gerrard------Lucas--------Hendo-----Downing
----------------Suarez-------Sturridge------------
Gerrard to tuck in/roam a bit.