So at the start of next season, with everyone back and healthy .. we have Osman, Pienaar, Arteta, Fellaini, Cahill and Rodwell who play in center midfield.
I have no idea who to bench from that lot and who gets to play in the middle .. why would Rodwell stay if he doesn't get to play? might as well go sit on the bench for a CL contender. Osman has shown what he can do when played in the right position against Chelsea and ManU. Arteta is probably the best playmaker. Fellaini has shown he can be the best DM in the world on any given day. Cahill has been a great player throughout the decade and his goalscoring really can't be missed. Pienaar is better in the middle, where he gets the space to move around and make things happen, than on the wing.
With Moyes as manager, there's probably thee CM spots available in a 4-5-1 lineup. Gun to head I'd probably say Arteta, Fellaini and Cahill in a more attacking role, but I just as easily would agree with any other combination.