Arsenal’s unbeaten run ended at 22 games following a 3-2 defeat away to Southampton on Sunday. Much like how the season has been going for the Gunners, defensive issues once again became an achilles heal. The rare victory for the Saints came after a woeful stretch of accumulating just five points in their last dozen Premier League matches.

Injuries and suspensions forced a plethora of defensive changes for Unai Emery’s side on the south coast. Rob Holding and Sead Kolasinac were unable to travel for the match due to injuries, while Shkodran Mustafi and Sokratis both served one-game suspensions due to receiving too many yellow cards on the season. Along with this quartet of defenders on the sidelines, Arsenal also welcomed back Laurent Koscielny and Nacho Monreal into the starting XI following injuries of their own.

Obviously having this many issues at the back is hardly ideal. Coping with four defensive absences, five if including Dinos Mavropanos, would be tough on any team. However, this was not the first time this season that the Gunners have endured defensive woes. Arsenal have astonishingly not taken a lead into halftime during league play and have also allowed as many goals as Crystal Palace, and the same as Liverpool and Tottenham combined.

SEE MORE: Schedule of Arsenal games on US TV and streaming

Although Mustafi and Sokratis will be available for their next match, the north London club must take full advantage of the upcoming January transfer market to strengthen the team’s defense. Much like Arsenal, Liverpool was previously in a very similar situation defensively in recent years. The Reds had plenty of fire power, like Arsenal, but were shaky in defense. Nevertheless, after transforming their back line with the additions of Virgil van Dijk and Andrew Robertson, as well as Alisson between the sticks, Liverpool are currently in the midst of a title scrap with Manchester City.

Arsenal need to follow suit and strengthen their leaky defense if they want to challenge at the top of the Premier League. Center back is certainly the most important area of need and Emery has acknowledged that the club will pursuit a player in this area come January. “If we can take one player to help us at centre-back, I think it’s a good option,” claimed the head coach prior to the Southampton defeat. “But a transfer is not easy.”

Emery followed up this sentiment after the loss on Sunday by claiming that spending big in January may be difficult. “It’s not easy, but I don’t believe a lot in this transfer window because there’s not a very big possibility with the players,” said the coach. “The club is working and only if some players can help us with a high level or better than [what we already have].” This could, however, be tactical as it does not put the club in a good position if he was to claim that they have plenty of money to spend.

Napoli’s Kalidou Koulibaly is undoubtedly the best center back ‘available’ in the January transfer window. The Senegalese defender would be a perfect fit for the Gunners, however, the Italian side have reportedly quoted teams around £90 million for their highly-rated player. It would be seriously surprising if Arsenal were to enter the Koulibaly sweepstakes, but he is the one player that they need the most.

If the Gunners chose not to, or just simply cannot, splash for Koulibaly, Sven Mislintat will have to put his magic to work. The head of recruitment at Arsenal, Mislintat is widely considered one of the best eyes for young talent on the planet. While a world-class central defender is desperately needed at the Emirates, the former Borussia Dortmund scout could be on the lookout for a cheaper alternative. However Arsenal decide to handle the January transfer market, strong reinforcements are an absolute must.