Mikel Arteta has said Arsenal are ready to enter the January transfer market should their squad remain as "exposed" in recent times.

The Gunners are without five players for Thursday's match at home to West Ham, a match where victory for Arsenal will see them regain top spot in the Premier League from Liverpool.

Thomas Partey, Jurrien Timber, Fabio Vieira and Takehiro Tomiyasu are all still sidelined, however, while Arsenal's Kai Havertz is banned following five yellow cards so far this season.

Arsenal spent more than £200 million ($256 million, 230 million euros) recruiting new players to the Emirates ahead of the current campaign, including their £105 million club-record signing of Declan Rice from the Hammers.

The England midfielder was joined at the Emirates Stadium by Havertz and Timber after Arsenal went on a spending spree, having missed out on the Premier League title despite being top for 248 days last season.

Arsenal manager Arteta has no certainty over when his injured quartet will be back in action and with a packed festive fixture schedule testing the depth of all Premier League squads, the Spaniard is prepared to bolster the Gunners' squad during next month's transfer window.

"At the moment, it is very difficult. We are really short," Arteta told a pre-match press conference on Wednesday.

"We have positions that we have been very exposed for the last six weeks and hopefully we are going to get players back. In what condition and when?

"That's a question mark and as well because we have some long-term injuries still for certain players that give us a lot of versatility and that's an issue."

Arteta added: "We have certain targets, ideas if things happen. As well, we don't know how the squad is going to look in two weeks' time and you have to be always prepared for that.

"But it is a very, very tricky market that shifts very quickly and it is quite unpredictable as well -- and you have to be prepared. We will be prepared and we will try to make the right calls.

"If there is something that we can (do to) improve the squad and that needs appear, and we cannot fulfil it with players here, we are always going to be open to do that because we want to be stronger."