I play him at CM, he is 'accomplished' in this role, although his natural position is AMC. In his personal details he is described as 'midfield playmaker' so when I play him, I give him the playmaker role with lots of creative freedom. I would play him in the AMC role, but my formation is 4-2-2-2 with 2 wingers (hazard and messi) and 2 CM (iniesta/pastore/henrique)
We still win nearly all our games but everyone else gets ratings of around 8 and Iniesta has okay morale and very average ratings, and for a player who is supposed to be in his prime (30) and with amazing attributes, i would expect more from him tbh.