On the contrary, I think the potential reward to the club from promotion is greater than the potential reward of selling him with only 6 months left on his contract.
If we are ever going to achieve the owner's vision, we need to get promoted. That is more important than turning over a couple of mill from a player sale.
For that reason, given that he's an important first XI player, I can't see him leaving in January (unless we are 20 points clear of third place!) - we will refuse all realistic offers. He may well not want to sign a new contract, which is up to him, but I'm sure he will see out the season with us.