The Gunners have lost Per Mertesacker to a long-term injury.
The German picked up a knee injury in the recent friendly with Lens, with scans later revealing he had ligament damage.
He has now undergone surgery and reports suggest he will be missing until the new year at the earliest.
That leaves Arsenal short on numbers in the centre of defence, especially with Laurent Koscielny taking an extended break following his exertions with France at Euro 2016.
And Wenger has admitted that he will be forced to sign another defender because of Mertesacker’s injury.
“I do not know how long he will be out but it is definitely going to be for a few months,” he told the Daily Mail.
“We need cover. We play some young players on Thursday (against the MLS All-Stars) but with Per being out, we are now a little short and I will have to bring somebody in.”
While Mertesacker’s injury is something of a disaster at present, it could prove to be a blessing in disguise in the long run.
It has long been argued that the Gunners were in need of another top class central defender but so far Wenger has failed to bring one to the club.
Mertesacker’s injury has forced his hand though, and perhaps he will now try to sign the quality defender that Arsenal fans have been craving.