In the last five or six years, it has not been a regularity for Arsenal to have a selection dilemma in the two centre-back positions. Since the days of Per Mertesacker and Laurent Koscielny, centre-backs have drifted in and out of Arsenal line-ups with most failing to impress. However, since the arrival of Mikel Arteta, Arsenal's defense has been shored up for the most part. Partnerships are beginning to form and serious candidates for Arsenal's future starting centre-back options are making themselves known. The Arsenal Boss has the unenviable job of choosing a partnership to stick with as we approach the most critical part of the season, but who will he choose? Let's look at the options.Gabriel MagalhaesArsenal's £23 million pound signing has enjoyed a first season in England of mixed emotions. The Brazilian started his Arsenal career in style, scoring on his debut and despite Arsenal falling out of form, Gabriel was performing brilliantly individually. He even managed to win back-to-back-to-back Arsenal player of the month awards, highlighting the impression he had made. However as Arsenal's form finally seemed to be turning around, Gabriel's fell away. He caught Covid-19 and has struggled to get back to the heights he started at since.

Gabriel's style is aggressive, pushing up on his opponents and as a large man (6'2), he is not afraid to get physical. Unfortunately, as much as his aggressiveness is his strength, it can also be his weakness. He can sometimes be caught out of position and can be prone to making rash challenges. This was seen with his, albeit harsh, second yellow against Southampton and mistimed challenge that saw Fulham score a penalty at the Emirates.

While Gabriel has his weaknesses, many still believe him to be Arsenal's best centre-back and at just 23 years old, the Brazilian will only improve.Pablo MariMari was signed from Flamengo on loan in January of 2020 before his deal was made permanent in the summer for a fee believed to be £8m. The Spaniard arrived injured and was limited to very few appearances before he was injured again and out until December. Since his return, however, Mari has become an assured and confident presence in Arsenal's defense. He is not the fastest but makes up for it with a superb reading of the game, drawing comparisons to Arsenal's 'BFG' Per Mertesacker.

While many would point to Gabriel as the more talented center-back, Mari has the instant advantage of fluency in English, something which Gabriel is still working towards. This undoubtedly allows him to better communicate with his fellow center-backs. Of Mari's 12 starts in all competitions this season, five have resulted in clean sheets for Arsenal, with 10 goals conceded overall.

David LuizArsenal's second Brazilian centre-back, David Luiz was signed from Chelsea for a reported £8m in 2019. He endured a tough start, playing throughout the end of Unai Emery's Arsenal tenure and making a number of high-profile mistakes but two performances that can be described as nothing short of incredible in Arsenal's 2020 FA Cup triumph undoubtedly won over most Arsenal fans. Since then, Luiz has served as one of Mikel Arteta's key men, leading on and off the pitch and presenting one of Arsenal's most solid centre-backs.

Luiz was unfortunately injured recently but aims to return in the next few weeks surely making himself a candidate for Mikel Arteta should Arsenal reach the Europa League final.

Rob HoldingRob Holding is a player that like so many Arsenal players, constantly seems to split opinion among the fanbase. He signed for Arsenal in 2016 from Bolton Wanderers for just £2m. In his time at the club thus far, he has won two FA Cups, starting the final of both and both times beating Chelsea.

When talking about the Englishman it's possible we could have been talking of a top center-back but a ruptured ACL injury in 2018 stopped Holding in his tracks. He had been at the center of an Unai Emery unbeaten streak and performing at an excellent level at the young age of 23. Unfortunately as often is the case with players suffering from the fallout of an ACL injury, Holding has struggled to regain the form he once had. This season, however, has shown some signs of measured, talented center-back once touted a future England player.Advert InsertedMikel Arteta put his faith in Holding at the start of the season, preventing his loan move and offering him a new contract. Holding has started the most Premier League games of any of Arsenal's center-backs, keeping nine clean sheets in his 23 starts. The downside to Holding preventing many Arsenal fans from placing their faith in him is his, although rare, mistakes. Losing out on a header to Raheem Sterling that led to a loss against Manchester City is one example, and he can commonly misplace passes that can force unneeded losses of possession.

It is unclear if Mikel Arteta sees Holding as a long-term option for his project but in important games his faith has been repaid, inevitably placing him high up in starting options.

PartnershipsWhile looking at each individual center-back is easy, the more important and ultimately difficult question is to ask which partnership works best.

Pablo Mari and Rob Holding is a partnership that looks to be a favourite of Arteta's. While the pair have only started six games together in all competitions this season, in those six they have kept four clean sheets. Arsenal have won five of the six also, with the only loss being against Manchester City. This is the partnership Arteta chose to go with in two games very significant to his future at the club. Chelsea at home and Slavia Prague away. This would suggest he is most likely to stick with the two, but other partnerships are available.With 12 starts in all competitions, Holding and Gabriel is Arsenal's most common center-back partnership this season. Of these games, four ended in clean sheets. Admittedly a lot of these games came in Arsenal's barren period, but the overall return has not been great from this partnership. Both players are not the best passers and can in turn slow down Arsenal's build-up. However, in fairness, they did produce arguably Arsenal's best defensive performance of the season - a win and clean sheet at Old Trafford.

While other pairings exist, the two above seem to make the most sense. Gabriel and Pablo Mari conflict in the fact that they are both left-footed, clashing in terms of passing patterns and balance. A partnership containing David Luiz also remains a possibility should Arsenal get to the final.

Mikel Arteta has an interesting decision on his hands when it comes to the players protecting his backline and the pairing he chooses to go will inevitably have a big impact on the way Arsenal finish the season and his future at the club.