Arsenal are working on a deal to sign Paris St Germain defender Layvin Kurzawa.
The PA news agency understands talks between the Gunners and the Ligue 1 giants have progressed past the initial stages.
Arsenal are short on options in defence due to a number of injuries and, if Mikel Arteta is to strengthen his squad during the current transfer window, adding numbers in that area was always going to be a priority.
Kurzawa, 27, is available on a free transfer in the summer when his contract expires but it is believed Arsenal are keen to do a deal to bring him to the Emirates Stadium this month.
Asked about his defensive headaches on Wednesday, Arteta replied: "We are playing with full-backs that are not full-backs.
"They are wingers or central midfielders and could we afford to lose full-backs? No, but we don't have any full-backs."
With Kieran Tierney and Sead Kolasinac both injured, Arteta is likely to have to field young winger Bukayo Saka at left-back against Sheffield United on Saturday.
Tierney had been a long-standing target for Arsenal and was finally recruited in the summer but his first months in north London have been thwarted by fitness issues.
Kurzawa would come in as a challenger to his position, with the France international starting just six league games for PSG so far this season.
Arsenal's original plans had been for a quiet January window but the need for an additional body at the back appears to have changed their outlook.
It remains to be seen if a fee can be agreed between the two sides but it is reported that Arsenal's head of football Raul Sanllehi is in charge of the talks.
Kurzawa has won three Ligue 1 titles, three Coupe de France crowns and a trio of Coupe de la Ligue trophies at PSG, having joined from rivals Monaco in 2015.