Arsenal’s defensive crisis has shown no sign of easing ahead of the north London derby against Tottenham on Saturday, but manager Arsène Wenger can at least breathe a sigh of relief that it has not deepened further. Having failed to sign an established center-back in the summer after the departure of Thomas Vermaelen, Arsenal are left with just four fit senior defenders heading into a run of games that also includes a crucial Champions League meeting with Galatasaray before visiting title rivals Chelsea on Oct. 5.

Mathieu Debuchy underwent surgery on his left ankle earlier this week, which Wenger confirmed will keep the French right-back out for around three months. Meanwhile, speaking ahead of the clash with their local rivals this weekend, Wenger confirmed that Spanish left-back Nacho Monreal remains sidelined with a back problem. Fearing the situation could worsen, Wenger selected a makeshift back four featuring three teenagers -- Calum Chambers, Hector Bellerin and Isaac Hayden -- as well as Francis Coquelin out of position in the midweek Capital One Cup tie against Southampton.

Wenger confirmed after a disappointing 2-1 home defeat that both Kieran Gibbs and Per Mertesacker were carrying knocks that meant it would be even more unwise to field them. “We are a bit short, yes because of the injuries we have,” he said, reports Arsenal’s official website. “You sit there and you think Gibbs couldn’t play because of a slight problem, Mertesacker is a bit on the edge and then we have no choice.

“Before the last game at Villa he had a little gluteus problem. He declared himself fit but at the moment we are so short that it's difficult [to play him] with the games he plays. We have to play on Saturday against Tottenham and then an important game on Wednesday against Galatasaray and then we go to Chelsea. To absorb all these games without being rested when you have a little problem is very difficult.”

Wenger did confirm that both Gibbs and Mertesacker “will be all right” for Saturday. There is some further good news with midfielder Mathieu Flamini likely to return after missing the past 10 days. “The only difference compared to Villa and Southampton is that Mathieu Flamini might be available again,” Wenger said. “He had a dead leg. I feel he should be back.”

Arsenal still have some long-term injury casualties. Theo Walcott, having ruptured his cruciate knee ligament in January and been given an initial six months prognosis, has recently seen his return delayed once more. Wenger stated this week that the England forward will return to full training after next month’s international break, meaning the earliest he could be available for selection is the end of October. The same is true for fellow wide man Serge Gnabry, who has not featured since March.

The most long-term of injury victims, Abou Diaby, did make his competitive comeback against Southampton, and Wenger believes a holding midfield role, in which Arsenal remain short of a commanding figure, could be the answer for the 28-year-old going forward,

“I feel because he was injured for a long time and he has the physical potential to win the challenges, to face the game will be easier for him than to play with his back to goal with the injuries he had,” he said. “I tried to develop him in a deeper role, I think he can do it. He can be very interesting because he has all the attributes to do it. After, he must love it as well because he's more of an offensive-minded player.”