Arsène Wenger has suggested that the chances of Arsenal signing a defender in the January transfer window have gone from possible to probable on the back of the continued injury problems for Laurent Koscielny. The France international had only just returned from nearly two months out with a long-standing Achilles complaint when a calf problem took him back out of the side. Wenger confirmed after the 4-1 win over Newcastle United on Saturday that Koscielny would be out for “a few weeks.” Having previously conceded that his squad was short on options at the back, the latest injury setback appears to have strengthened Wenger’s desire for reinforcements when the transfer market reopens next month.

“Well yes, with Laurent Koscielny's injury we're a bit cautious and we need cover,” he told Sky Sports.

As Wenger has himself cautioned, though, getting in the right players in January will be no easy task. In the hope that he could be prized away in the final months of his contract, one of the defenders Arsenal are thought to have been watching closely is West Ham’s Winston Reid. The New Zealand international center-back has been an important part of a West Ham team currently sitting above Arsenal in the Premier League table. But manager Sam Allardyce is adamant that they won’t risk having their season derailed by allowing Reid to leave in January, even if that means him moving for nothing next summer.

“He ain’t going anywhere,” Allardyce said, reports the Daily Mirror. “He is not going anywhere unless someone bids £20m or something like that. There is obviously not a lot I can do about that.

“If somebody flirts around with a measly offer because he is in the last year of his contract, we would make more money by keeping him and finishing where we are in the league than selling him and putting our good season in jeopardy. Because replacing him in January -- replacing anybody in January -- is a very difficult job indeed.”

Arsenal may have other irons in the fire. The Sunday People reports that Arsenal are “stepping up” their interest in Schalke captain Benedikt Howedes. The 26-year-old was part of Germany’s World Cup winning squad, when he operated as a left-back. Having also been deployed on the right of the defense, the versatility of the center-back by-trade will surely appeal to Wenger as he looks to cover for a consistent stream of injuries across his back four. However, especially given their progress to the last 16 of the Champions League, Schalke are unlikely to be acquiescing to the prospect of losing their influential skipper midway through the season.

Mikel Arteta’s continued injury problems, combined with injuries currently ruling out Jack Wilshere and Aaron Ramsey, have also left Arsenal light in midfield. A commanding deep-lying midfielder has long been conspicuous by its absence in the Gunners squad and, while Wenger has given no indication that he plans to finally address that deficiency in January, reports suggest that the club are eyeing up potential targets.

Brazilian publication Lancenet, in a report picked up in the British media, has stated that Arsenal are on the verge of signing Brazil international Romulo from Spartak Moscow. After a successful spell with Vasco de Gama and some impressive performances for Brazil’s Olympic squad in 2012, the defensively astute and dynamic midfielder looked on course for big things. But shortly after his move to Russia, Romulo suffered a cruciate knee ligament injury that forced him to miss nearly 18 months. He is now back in action, and was called into the Brazil squads in October and November, but would still be something of a surprise signing for Arsenal at this stage.

For different reasons, perhaps an even more unlikely transfer for Arsenal in January would be reported target Joao Moutinho. More of a playmaker than a defensive presence in the midfield, the Portugal international has been rumored to be the next big name to pass through the exit door at Monaco, with Arsenal one of the possible destinations. The Ligue 1 side’s progress through to the Champions League last 16, where they’ll take on Arsenal, always meant that scenario was unlikely to play out in January. And Moutinho has insisted he has no time for such speculation.

“I am not thinking about the January window, nor am I thinking about the end of the season,” he said, according to the Daily Express. “I don’t want anything to do with that. I am focused on Monaco.”