Perhaps Smith isn't necessarily the replacement for Dyer - maybe Sam sees a current memeber of the squad being able to step up/forward and take on Dyers role (N'Zogbia? or Troisi? or Milner?) - hopefully with less injuries, and with more end product.
Smith adss other qualities to the squad, and as a body, yes he is a Dyer replacement, but maybe not so much in actaul role.
Just a thought!
Good post imo-i hadnt thought of that.