Celtic will test Charlton’s resolve one more time for Alfie Doughty – and line up a short-term option if unsuccesful.
The Scottish champions have already failed in two bids for the Addicks star and will lodge a final offer before the transfer deadline a week on Monday.
But if it’s rejected they will look at alternatives, which are expected to be loan targets.
Celtic still see Doughty as the ideal solution to their left-back issues, even though he plays in midfield for the EFL side.
Celtic’s last offer was around £600,000 and they are likely to go in higher but they are not prepared to pay over the odds.
Charlton boss Lee Bowyer has previously admitted that £1million might not be enough but Neil Lennon’s side are unlikely to go that high, knowing they can get him for under half that on a cross-border deal in the summer.
Celtic could sign him on a pre-contract in January and then could secure him for a fraction of the transfer if he was to remain in England.
Lennon wants to bring somebody in to challenge Greg Taylor with Boli Bolingoli on loan at Turkish side Basaksehir.
Danish-American businessman Thomas Sandgaard was finally confirmed as Charlton's new owner on Friday and he immediately warned potential suitors that players would not be sold on the cheap.
He told Sky Sports: "That stops right here (selling for cheap). Period.
"That has nothing to do with it (size of the bidding club). Of course, if the price is right, we have sufficient replacement and Lee thinks it’s a responsible move, in terms of the squad, we’ll do it.
"But, otherwise, we’ll be conservative. We’re not going to sell players just to pay the wages of the staff or a tax bill, if something like that comes up.
"We’re not selling players for that reason. We’re only selling players if, financially, it makes sense, if it’s an offer that’s good enough and how hard we need to keep them on board."
