Laurent Koscielny has been nothing short of brilliant for Arsenal in his nine years with the club, but he appears to be on his way out of north London.
In the increasingly likely event that the Gunners lose their captain, their options in central defence look shabby, to say the least. Even if Koscielny stays, the club are hardly blessed in that department, with Shkodran Mustafi, Rob Holding, Calum Chambers, Sokratis Papastathopoulos, Konstantinos Mavropanos, Sokratis Papastathopoulos and Nacho Monreal joining him at the back.
It's not exactly an inspiring selection of centre-backs. With that collection of players, Arsenal certainly won't be challenging for the Premier League title. In fact, they'd be lucky to seal a top-four spot.
To determine just how screwed Unai Emery is next season, here's an assessment of each defender's quality and what level of football they should really be playing at.
I don't believe that Mustafi is an actual footballer. No, he must be a comedian or some kind of jester. He's doing a great job at making people laugh, to be fair, though Gooners won't find it remotely entertaining.
If you tried to hunt down a highlights reel of the German's time at the Emirates Stadium, you'd probably come up empty-handed. All he has done since his £35m (!!!) switch from Valencia is make error after error and leave his teammates worried.
Mustafi should be sent back to his home country at the next available opportunity, even if Emery has to drive him there himself. The club have apparently looked to offload the 27-year-old on numerous occasions but are yet to receive a high enough fee - they'd be well advised to accept whatever they can get.
Where He Should Be: German Third Division
Virgil van Dijk, Aymeric Laporte, Antonio Rudiger; these are the kinds of defender that will lead a team to glory, the type which you can use as a foundation for success. Holding isn't.
He's far from a disappointment, often looking like the sturdiest option for Emery. However, it has been obvious for most of his three seasons with the Gunners that the youngster is not at the required standard.
Mistakes come rarely, but outstanding performances are even less frequent. Holding regularly fails to make an impact in matches and would be better off plying his trade with a promotion-chasing Championship side.
Where He Should Be: Top-End Championship
Chambers was purchased too soon. Arsene Wenger would have had hardly any time to make a proper evaluation of the ex-Southampton starlet when he snapped him up as a teenager.
22 Premier League appearances in his only campaign in the Saints' first-team suggested this kid had potential and could develop into a superb central-defender. Unfortunately, there has been little progress after his switch to the Emirates in 2014.
Chambers is not at all a bad player to have in the squad, but he is clearly a weak link for elite opponents to exploit. He found his level at Fulham last term and should expect to be in relegation dogfights for much of his career if he wants to be a guaranteed starter in the top-flight.
Where He Should Be: Premier League Relegation Battlers
Injuries make it difficult to say whether Mavropanos has the right stuff for Arsenal. Some of his displays at the back have been rather impressive, but they are few and far between after fitness issues restricted the Greek defender to just seven matches in all competitions following a move from PAS Giannina.
Even when he was available, Emery seemed averse to selecting the 21-year-old. The coach will know more about his players' abilities than anyone else and evidently doesn't trust him when it really matters. Perhaps, they should simply cash-in and forget about this failed experiment.
You'd expect to see Mavropanos battling it out for a Qarabag or BATE Borisov on a Thursday night, occasionally making an eye-catching block before firing a bullet header past his own goalkeeper. You definitely wouldn't expect to see him guarding the net of a 'Big Six' team.
Where He Should Be: Europa League Randomer
Koscielny is yearning for a return to his native France, where he would be able to spend the remainder of his playing days at a slightly slower pace. Given that he is now 33, that probably sounds ideal.
Of course, he wouldn't make the cut at Paris Saint-Germain, but the drop-off in quality between Thomas Tuchel's team means that the Arsenal skipper would likely be challenging for a starting berth at nearly every other Ligue 1 outfit.
He's earned the right to leave London on his own terms, having been a superb servant for the Gunners. Let him go and enjoy what's left of his time on the field.
Where He Should Be: Any French Team That Isn't Paris Saint-Germain
Monreal in a back-four is a bad idea. Monreal in a back-five works splendidly. Emery is a fan of the latter formation and should, therefore, keep the Spaniard around.
The ex-Malaga man lacks the height for a two-man partnership in the heart of defence, whilst he has lost the speed which made him well-suited to the full-back position. However, his skill-set is of huge value when he has more cover around to make up for his short stature.
Anyone who doubts Monreal's competence in the Premier League should read up on what makes a solid defender. He's reliable, driven and actually makes a difference when handed a start. No wonder Emery was so eager to have him sign on for another year.
Where He Should Be: Arsenal
If he wasn't as slow as an asthmatic tortoise then Sokratis would be a first-rate defender. Even though he's a bit of a slouch across the turf, the Greek international is still superior to almost all of his alternatives, reading the game well and dominating aerially.
Much like Monreal, his faults are minimalised in a five-at-the-back system, making him a good fit for Emery and the Arsenal side he hopes to build; best make sure he's got some speedier centre-backs about, though.
Where He Should Be: Arsenal