Over his career BA is a 1 in 3 striker (or as near as damn it)
The last two years he's been nowhere near that and clearly is not the player he was. It would be churlish to not take into account the managerial merry go round since he came and the style of football we have mostly played. Warnock is renowned for improving players, he gave him the captaincy, presumably he sees something in him that others can't/won't see.
Whether Warnock wants him to stay and sign a new contract none of us know, one thing for sure if he does stay he will not be on anywhere near the terms he is now. I personally think he'd be better moving on. He's been here a while and probably change of scenery will benefit him. He could score12 goals between now and the end of the season and some fans will never accept he's any good.
As I've said before though he can't be forced out until the end of the season, if he leaves in January it will only be because he has received an offer acceptable to him and he wants to go.