At first glance, you might think no one.
The league leaders are ten points clear at the top of the Scottish Premiership table with a game in hand and will face second-placed Aberdeen in the League Cup final this weekend.
But Celtic are a team in transition and boss Brendan Rodgers will need to play his hand carefully when his second Celtic transfer window roles around – especially with a number of key faces seemingly drifting towards the Celtic exit door.
So what should Rodgers be focusing on when January roles around? Here’s the key areas he should look at…
Hanging on to stars
Perhaps it’s a good sign when top clubs are coveting your players but with the next transfer window looming close, Brendan Rodgers would do well to get assurances from his top names.
Most pressing of all will be the future of strike sensation Moussa Dembele. The Frenchman only joined the club in June on a four-year deal from struggling Fulham but he has already made a name for himself as one of Celtic’s top stars.
Icons from the club’s past have been emerging from the woodwork in recent days urging Dembele to ‘do a Henrik Larsson’ and become one of Europe’s top marksmen in the club’s famous hoops.
But with clubs like Manchester United, Chelsea, Arsenal and even Bayern Munich reportedly interested in the France Under-21 cap, it may take more than that to convince Dembele to stay.
And he’s not the only one. Defender Jozo Simunovic looked certain to leave the club in the Summer, with Sky Sports interviewing the big centre back in Turin as he awaited the completion of a deadline day move to Serie A side Torino. That move eventually collapsed after the clubs failed to agree a fee.
While his case may not be quite as pressing as Dembele’s, Jozo has made eight appearances for Celtic so far this season and Rodgers may not be quite so keen to see him go this time around.
Jordan Mutch
The club have reportedly been weighing up a cut-price deal for the Crystal Palace midfielder and a £2.5million move in January could certainly be on the cards.
At just 24-years-old, Mutch could be an excellent addition to Celtic midfield that already boasts huge amounts of talent.
At the reported price tag, Mutch would be a steal, having cost Palace nearly double that just two years ago – and QPR were more than happy to hand over £6million for his services.
Mutch started his senior career at Birminghgam City and, after loan spells at Hereford United, Doncaster Rovers and Watford, really hit the heights when reunited with old Vicarage Road gaffer Malky Mackay.
Steven Gerrard
The former Liverpool icon has been repeatedly linked with his former boss in Rodgers and recently turned down the chance to manage MK Dons.
Could Gerrard be tempted to make the move to Glasgow? Rodgers revealed last week that he had been in regular contact with the 36-year-old.
He is understood to be in line for a coaching job at Liverpool if he decides to hang up his boots with a number of offers on the table from around the world, the former England captain will have plenty of time to mull over his options before the January window opens.
Central Defender
Rodgers has relied heavily on Mikael Lustig and Erik Sviatchenko so far this season with the pair already making more than 40 combined appearances.
Kolo Toure signed for the club in the summer but has had a less than spectacular start to his Celtic career after claiming he made the ‘mistakes of a 16-year-old’ to cost his team the game against German side Borussia Monchengladbach.
Rodgers faced a defensive crisis in July when Sviatchenko was ruled out for three weeks ahead of the club’s Champions League tie against Astana and he will keen to ensure he does not encounter the same problem again.
Reports suggest he is looking at highly-rated 18-year-old Ezri Konsa and was recently spotted in the stands to watch him in action for Charlton Athletic in League One.
Up front
With Moussa Dembele looking increasingly likely to move on from Celtic, Rodgers could decide to use some of the potentially huge transfer fee to invest up front.
Currently the hoops have the Frenchman and hot-shot Leigh Griffiths blasting in the goals for them but if the former does decide to move on, Nadir Ciftci, who has scored a total of four goals since moving to the club in 2015, may not be viewed as a suitable replacement.
Irish striker Robbie Keane has been linked after deciding not to continue his time in the MLS with LA Galaxy. At 36-years-old, he might not be one for the future but he does have previous with the club scoring an incredible 12 goals in 16 appearances while on loan in 2010.
After scoring 83 in 125 with LA Galaxy, Keane could provide a good short-term option – and priced up at 6/1 to return to Parkhead, it would seem the bookies agree.