BBC's view of the situation.
Cardiff City: 'Underperforming squad needs strengthening'
Dafydd Pritchard
BBC Sport Wales
What do Cardiff need?
Goals and pace. Cardiff are the joint lowest scorers in the Championship this season and, in truth, their attack has been blunt for years. As well as finding a centre forward who can finish, the Bluebirds need to address their lack of pace in the final third.
Likely business?
Manager Omer Riza believes he will get some financial backing and, like his predecessor Erol Bulut, it's the attack that he's keenest to strengthen.
As Cardiff battle against relegation for a third season out of four, however, they are going to be a tough sell for any prospective signings.
Any notable departures?
Losing centre-back
Mark McGuinness to Luton in the summer was a blow but it's a measure of Cardiff's current standing that not many – if any – of their players are likely to attract interest in January.
Some youngsters might leave on loan, fringe players could be moved on, but the first-team regulars are unlikely to be poached anytime soon.
How key is the window?
It will certainly have a big bearing on whether or not Cardiff stay up. There was actually a little cautious optimism at the start of the season after some encouraging summer signings but that has proved to be misplaced so far.
On paper, this looks like a comfortable mid-table Championship squad, but it's underperforming and in need of strengthening.