I don't think Gerrard fits into the midfield Rodgers wants to play. He is not in the mould of a Rodgers midfielder and I think definitely has to take on a different role to be effective in the side. Take a look at this article which compares some of Gerrard's passing stats with Joe Allen's:
http://blog.oddslife.com/2012/09/does-gerrard-have-a-place-in-rodgers-midfield/
