Lua Lua still puzzles me, if he had impressed this season during his loan spell and good and dandy but he hasn't had the opportunity so he must be low down the pecking order and yet we sign him on contract.
I don't think you're alone with that. Some people have hypothesised it may have been about driving down the asking price, some think it may have been related to the insurance issue surrounding the problems signing him in august (it has been a week over a year since the injury that put him out of action and could have been an insurance deadline). He got injured early in the season, and while he was out Noone has established himself, but that doesn't explain why he has only been given 50 minutes in the last 9 games.
Perhaps him leaving us more vulnerable at the back has led to gus being reluctant to use him while we're struggling to win.