Charlton Athletic face a battle to keep hold of Alfie Doughty as the January transfer window opens, with the left-sided player able to sign a pre-contract agreement with non-English clubs from Friday.

That's because the 21-year-old is out of contract in the summer, and it has form has caught the eye of plenty of clubs, notably Celtic and Rangers.

If Doughty does move to either Glasgow outfit, the Addicks will be entitled to less compensation than they would otherwise receive, so it's something the Londoners don't want to happen.

Of course, there's nothing stopping any club agreeing a fee with Charlton for a January transfer, although the hamstring injury the player is currently suffering from may put suitors off next month.

Here we outline the current situation involving Doughty and assess whether he will secure a transfer away...

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What do we know so far?

Firstly, we know that Celtic are very keen on the player.

They made several attempts to sign Doughty in the previous window, with key figures at Celtic Park desperate to bring the youngster north of the border.

However, it has now been suggested that Rangers want Doughty as well. Of course, Charlton want to keep their star man, who is going to have a big decision to make in the coming weeks.

Is an exit likely to happen?

The longer the player goes without signing a new deal at The Valley, the more likely an exit seems.

Having said that, Doughty will want to consider his options. He is free to talk to Celtic and Rangers in 2021, which will allow him to fully assess the offers out there for him.

Meanwhile, English clubs will know that they can get him at a knockdown price next month as his deal runs down.

So, it's all on Doughty. He has to decide where he wants to play and the picture will look a lot clearer in the next month.