Manager Alan Pardew has told Demba Ba that even if he stays with Newcastle until the end of the season he will be sold in the summer if the release-clause remains in his contract.
Speculation is once more rife that the 27-year-old Senegal international will leave Tyneside next month when the £7.5million clause in his contract becomes active again during the winter transfer window.
The 51-year-old Pardew said: "Really and truly this window is the key, I think, because if Demba goes in this window, it will cause us a problem. I think he will stay, but there's a possibility he could go because of the clause that's still in force."
He added: "In the summer, I won't let it run until the summer. I'll do something about it.
"We will either move Demba on or we will secure him in the summer."
Ba, who has 11 goals to his name so far this season to go with the 16 he scored during the last campaign, has been linked with Arsenal, QPR and Paris St Germain among others in the run-up to the transfer window.
But Newcastle spent much of the summer awaiting a bid which would trigger the clause and it never came.
Meanwhile, Pardew confirmed that the ankle injury suffered by midfielder Vurnon Anita at Manchester United is only bruising and although he will miss Saturday's trip to Arsenal, he is not facing a lengthy spell on the sidelines.