As you say, he may not have rejected the offer, but it's been on the table for 9 months which tells us he has no intentions of signing it if he can get something better, meaning he does not want to be here, the contract offer should be withdrawn if that's the case.
Also if he hasn't signed by the end of the transfer window, we won't be able to sell him, as he is free to speak to clubs in January, so they aren't going to pay a fee for him when they can sign him for free.