Arsenal have been struggling with injuries this season.
The likes of Hector Bellerin and Kieran Tierney have missed significant chunks of the season, and Calum Chambers will miss a large part of 2020 following a serious knee injury.
And after disappointing results of late despite improved performances under Mikel Arteta, one former Gunners star has urged the club to act.
"There's not much time to go [in the January transfer window], but I'd like to see some defenders in," Charlie Nicholas told Sky Sports. "We need two defenders in.
"I don't mean to be disrespectful but you see David Luiz last night and you see the mess Shkodran Mustafi made for the goal. It's still evident that Arsenal are bad at the back.
"Hector Bellerin coming back is obviously a boost but there are problems all over the defensive set-up. We need defenders to come in and help the current situation."
Arsenal have been linked with Dayot Upamecano for some time, but a deal for the RB Leipzig star in this transfer window looks unlikely.
Meanwhile, new links to Shakhtar Donetsk centre-back Mykola Matviyenko seem slightly more promising, with the defender dropping a hint about his future on Instagram following links with the Gunners.
