This season, Per Mertesacker hasn't played at all. His predecessor, Mikel Arteta, managed just six league starts in his two years as club captain, while before that, then-skipper Thomas Vermaelen started only seven times in his final campaign. It means that, in Arsenal's last 141 league games, their captain has started only 13 times.

This isn't a new development, of course, but it's worth considering this weekend as Arsenal welcome back Arteta -- now serving as one of Pep Guardiola's assistant managers at Manchester City. Arteta's official period of captaincy might not have been particularly successful, but he should be welcomed back as one of the most important players of Arsenal's Emirates era.

That might sound peculiar, but it's worth remembering quite what a state Arsenal were in when Arteta joined from Everton in 2011. Arsenal had just been humiliated 8-2 at Manchester United, unquestionably the lowest point of Arsene Wenger's reign and a defeat that suggested they had little chance of maintaining their Champions League status. Wenger had previously suggested the club wouldn't lose Cesc Fabregas and Samir Nasri that summer, and doing so would imply Arsenal had no ambition. Then Fabregas fled to Barcelona, Nasri moved to Man City, and Arsenal desperately lacked midfield creativity, experience and, of course, leadership. Three days later, on the final day of the transfer window, Wenger rolled the dice.

Having previously made his dislike of "deadline day" clear, Wenger completely reversed his stance. In the space of just over 24 hours, he brought in no fewer than six players: Park Chu-Young, Andre Santos, Thomas Eisfeld, Yossi Benayoun, Per Mertesacker and Arteta. It was a weird and wonderful mix -- the first three made extremely little impact, Benayoun provided some crucial contributions but was a mere loanee, while Mertesacker and Arteta proved transformative.

In a squad lacking natural leaders -- the armband passed to Robin van Persie, a technical leader rather than a proper captain -- Mertesacker and Arteta took control. The two befriended one another while staying at the same hotel shortly after their last-gasp signings -- Arteta would remain there for three months, while he struggled to find a suitable house in London.

They sorted Arsenal out. Mertesacker commanded the backline, providing an experienced head alongside Laurent Koscielny, an impetuous defender in his first couple of seasons, or Vermaelen, who had a tendency to move too high up the pitch and be caught ahead of play.

Arteta, too, was crucial for providing balance. Having generally played an attacking role at Everton, he sacrificed himself to play a deeper role and ensure Arsenal had balance in their midfield, protecting the defence to prevent a repeat of that Old Trafford embarrassment. As the season continued, Arteta developed a good relationship with Alex Song and occasionally pushed forward into attack more, but his solid, reliable positioning was fundamental in Arsenal protecting their nervous defence properly.

"A big part of my job is to get the balance right, to get everyone together and make the team work more smoothly at both ends of the pitch," Arteta explained, just two months into his Arsenal career. "It's about making everybody aware of how to be in the right position when we have the ball, so that when we lost it we can win it back as soon as we can."

That was on-field leadership. Off the field, the Spaniard was equally crucial, describing himself a "policeman" who ensured everyone followed the rules, at a time when Arsenal had a young squad that occasionally lacked the self-discipline of the "Invincibles", for example.

He was crucial in bringing the squad together -- at a time of plenty of new arrivals and not everyone speaking the same language, Arteta was almost interpreter. He spoke fluent English and Spanish, a good amount of French after his 18 months at PSG, and a touch of Italian and Portuguese too. Therefore, at a time when obvious language-based cliques may have formed, or new individuals may have felt separated from the wider group, Arteta was the link that ensured Arsenal had a united dressing room.

Arteta combined this with a focus and drive that was, alas, somewhat rare in Arsenal's dressing room at this time. He happily admits to being a footballing obsessive, going over incidents thousands of times in his head after matches, unable to switch off from the process of learning about football and studiously watching matches in the evenings when he should be relaxing. During this period, when the likes of Denilson, Andrey Arshavin and Marouane Chamakh were in the dressing room -- hardly the most professional or committed footballers -- it was, again, crucial in improving Arsenal's mentality.

Arsenal finished third in Arteta's first season, but were then rocked by the departure of the inspirational Van Persie. Santi Cazorla, Olivier Giroud and Lukas Podolski came in and settled quickly -- again, partly because of Arteta's linguistic skills, his leadership and his "policeman" approach in the dressing room. Arsenal started poorly, but again battled back into the Champions League places. Arteta was one of surprisingly few constants between the two seasons, probably the two most difficult in Wenger's period at the club, and was widely regarded as one of the club's most important players.

Having been made official club captain in 2014 after Vermaelen's surprise move to Barcelona, Arteta's final couple of seasons were dogged by injury, and he announced his retirement with a remarkably frank description of his diminished ability.

"For the last few months that I wasn't good enough to represent this club on the pitch," he admitted. "In the last few months, I probably didn't deserve to be here... for me, the standards you need to play for this club, it cannot be eight out of 10. It has to be 10 out of 10. When you cannot deliver that, it is not good enough."

Even upon his departure, Arteta was setting the standards and laying down the law. He deserves a fine reception upon his return to the Emirates this weekend, and is a good example of how Arsenal's leadership has, in recent years, rarely come from the club captain