The Cottagers have conceded 31 goals in the Premier League, more than any other team, and it is clear which area they need to strengthen in January.
The London outfit wanted to sign Dedryck Boyata from Celtic in the summer transfer window, and they are looking to rekindle their interest in the Belgian defender.
According to The Daily Mail, Fulham is interested in signing the Belgium international defender in January, but they are not willing to pay £9m for the 27-year-old.
Boyata is arguably one of the best central defenders in the Scottish Premiership, and he is absolutely vital for Celtic to have a successful season.
He will be a free agent next summer and Celtic now have a big decision to make. They can sell him now and if Fulham come back for him again in January, Boyata may find hard to resist a move away from Parkhead.