He's either leaving this January or he isn't. If he does, and we get the money to buy a suitable replacement (and some change, hopefully) all well and good. So long Charlie and thanks for all the goals.
If he doesn't, we need to be really careful we don't end up with a player who's a shadow of his former self/just going through the motions till he goes in the summer. One really good way of doing that would be for people to take out their frustrations on him when he's on the pitch. If he does stay, we need him to be firing on all cylinders, not just for the rather obvious reason that we need his goals but also so that his sale value holds for when he does go in the summer. An out of form Austin benefits no-one
Trouble is knowing the sort of person / personality that Charlie is he may find it difficult until the end of Jan to go out full stop to score goals / give his all as he would not want to risk getting an injury and scuppering any move now he's made it official he wants to go.