Who could leave?
Alexis Sanchez
The Chile international is out of contract at the end of the season and almost left in the summer when Arsenal accepted a £60m offer from Manchester City.
The move fell through when Arsenal failed to bring in Thomas Lemar from Monaco, leaving both City and Sanchez unhappy.
But there is a chance the Premier League leaders could come back for the former Barcelona man - despite him having just six months left on his deal.
An offer of around £40m could arrive - leaving Arsenal facing a tough decision at the midway point of the campaign.
Potential fee received: £40m
Mesut Ozil
Like Sanchez, Arsenal's German playmaker is also out of contract in the summer and could leave for free.
So an offer in January could tempt Arsenal into doing business, despite Wenger's insistence that he would be staying.
Manchester United are interested, while reports in Spain suggest Barcelona are also keeping tabs on the former Real Madrid man.
But recent reports suggest that the Gunners may be able to convince Ozil to sign a new contract to keep him at the Emirates beyond the current season.
Potential fee received: £30m
Jack Wilshere
Arsenal's midfielder could well look to move on in January to give himself one final shot of making England's World Cup squad.
Contract talks are due to take place this month between the player and the club and as yet it is far from clear whether he will extend his stay in north London.
Even Arsene Wenger has suggested Wilshere could leave, with West Ham said to be interested.
Potential fee received: £10m
Olivier Giroud
The France striker rejected a move to Everton the summer to stay and fight for his place at Arsenal.
But he is finding opportunities few and far between this season and his spot in France's World Cup squad is now far from clear.
So to guarantee his spot on the plane he could push for a move away, with Everton still believed to be keen on the frontman.
Giroud has spoken openly about his need for more action and he could finally push through a move once the window opens in the new year.
Potential fee received: £30m
Theo Walcott
The winger has barely had a look in this season and a move away in January could be appealing in a bid to secure some first team football
Everton are believed to have already made an approach to Arsenal to ask about the winger's availability.
He is on big wages and Arsenal could be open to getting him off the wage bill - especially with Reiss Nelson making a breakthrough in recent months.
Potential fee received: £25m.
Who could arrive?
Thomas Lemar
It's unlikely, but Arsenal could make another move for Lemar if they decide to sell Sanchez in January.
Monaco have not entirely ruled out cashing in on their winger when the window opens, although they have stated that the summer is a more likely option.
The France champions are already out of the Champions League, however, and Lemar has had a disrupted season due to injury so Monaco could be tempted to sell.
Arsenal bid £90m for Lemar in the summer but any offer in January would be far lower.
Potential transfer fee: £70m
Nabil Fekir
The Lyon playmaker has had a superb start to the season and is on Arsene Wenger's wanted list.
The Arsenal boss sees him as a possible replacement for Mesut Ozil, so should the Geman move then Wenger could make an early move for Fekir.
The France international's father - who is also his agent - has previously suggested that Fekir is keen on a move to Arsenal.
Potential transfer fee: £50m
Julian Draxler
Arsenal have already sounded out Paris Saint Germain about Draxler's potential availability in the summer.
The German has had to play in a deeper role this season following the arrival of Neymar and Kylian Mbappe and a six month loan move could appeal to him, especially with the World Cup looming large.
It could also allow Arsenal to sell Alexis Sanchez and give them some breathing space until the summer in terms of bringing in a long term replacement.
Potential transfer fee: Loan.
Steven N'Zonzi
The Sevilla midfielder was linked with Arsenal in the summer and could be on his way out of the La Liga club after falling out with his coach.
According to Spanish sports daily AS, N'Zoni's relationship with Eduardo Berizzo has broken down with the Frenchman storming off the pitch at half-time in his side's 3-3 draw with Liverpool in the last round of the Champions League group stage.
He has a release clause of £35m.
Potential transfer fee: £35m.
Jonny Evans
Arsenal had a bid knocked back for Evans in the summer but the West Brom man remains a big target for Arsene Wenger.
The Gunners boss is happy to wait until the summer before making another move, but should he be given any indication that Evans is available then he will look to beat Manchester City to the centre-back.
Evans has 18 months left on his deal at West Brom and will not extend his stay, so they could look to cash in now.
Potential transfer fee: £30m.