Arsene Wenger has lamented his failure to sign a defender in the summer transfer window, describing the market as "very difficult".
Arsenal have already been caught short at the back after both Nacho Monreal and Mathieu Debuchy suffered injuries. The latter of the two is set to be out until the new year with ankle ligament damage while Monreal is expected to return in October.
At the moment Arsenal's back four appears strong. Calum Chambers can fill in for Debuchy and right-back and Kieran Gibbs is Wenger's first choice left back anyway.
However, one more injury to any one of the back four, including Laurent Koscielny and Per Mertesacker, will leave Wenger with no choice but to turn to his youth team. Hector Bellerin has already been called in against Borussia Dortmund while Isaac Hayden made his debut against Southampton.
Arsenal had an impressive summer transfer window. Wenger spent more money than he he ever has done by bringing in Danny Welbeck, Alexis Sanchez, David Ospina, Debuchy and Chambers. However, he was criticised for not signing another centre-back to cater for the loss of Thomas Vermaelen.
But Wenger attempted to calm to storm before it gets worse. The Frenchman reminded fans and pundits that signing a new defender is not easy. He also said that only bad luck has found them in this situation.
He told reporters: "We have been unlucky to lose Monreal and Debuchy but it's very difficult to buy defenders in this market.”
Indeed, Arsenal were on the market for a new defender, but with Koscielny and Mertesacker firm favourites, any new signing would come in on the basis of being a back up. Most defenders would not favour such a move as seen in the Kostas Manolas saga.
The Greece international looked set for a move to the Emirates but talks apparently hit an impasse over first team opportunities. Manolas eventually joined AS Roma as a result.
Equally, a new defender would have likely limited Chambers's involvement in the first team and thus hampered his development. The 19-year-old has thoroughly impressed since his £16 million move from Southampton and has been tipped to be a major part of Arsenal's future success.
Arsenal play Tottenham on Saturday at 17:30.