Every dressing room needs leaders. Players willing to take charge and inspire their team-mates to greater performances. During Arsene Wenger's 22 years at Arsenal, his best teams always had inspirational characters capable of leading the club to silverware.
The man who has become Arsenal's latest signing is someone capable of fulfilling this role for new manager Unai Emery. The former PSG boss is looking to shape the Gunners in his image , and is hoping Greece international centre-back Sokratis Papastathopoulos can be a leader for him on and off the field.
There is no doubting Sokratis' credentials for the latter, having captained teams throughout his career: from becoming AEK Athens' youngest-ever captain at just 19 and then wearing the armband under both Peter Bosz and Peter Stoger during the 2017-18 season for Borussia Dortmund.
When Pierre-Emerick Aubamayeng missed training at Dortmund as he angled for a move to Arsenal, Sokratis was one of his most vocal defenders. The Greek centre-back insisted that the rules must be adhered to, but that Aubameyang should be forgiven after all he had given the club.
"If a player makes a mistake off the pitch, we have a duty to help him so that does not happen again," Sokratis told Reviersport in January. "And if you address Auba: Of course, he was not on time. But we also have to see what he has done for this team over the past four and a half years. The rules must of course be respected. But the most important thing is to solve such problems within the group without drama."
Along with fellow new signing Stephan Lichtsteiner , Sokratis will help instill better discipline in the Arsenal dressing room. They will immediately become senior members of the squad and help address a huge problem which saw the Gunners miss out on silverware and a top-four spot in Wenger's last season in charge.
After their 3-0 humiliation by Manchester City in the Carabao Cup final, Arsenal were widely criticised for having 'no leaders' in their team , but at the time, that claim was nothing new. At the start of the 2017-18 season, Wenger reacted angrily to comments that Arsenal lacked leadership on the pitch , and the criticisms go back even further than just last season.
Emery has done well to address the issue so quickly after his arrival, but on the pitch, he may find Sokratis lacking. In the same interview where Sokratis defended Aubameyang, he was forced to respond to claims from Bosz's assistant Hendrie Kruzen that his on-field displays had let Dortmund down, resulting in the Dutch coach's early departure from Westfalenstadion.
"It is unnecessary to answer," Sokratis said. "I've played at Borussia Dortmund for four and a half years, I've played more than 180 games for BVB. And I have always given everything. I will give my answer on the pitch. Of course, criticism is never nice. But it only affects me when it is justified. I do not consider this criticism justified."
However, Sokratis did not give his answer on the pitch either. Under Bosz's successor Stoger, his output did not increase. Whereas once he had been the rock at the heart of the Dortmund defence, last season he was an evident crack in a crumbling structure.
In 2017-18, he set personal worsts for aerial challenges won and interceptions, finishing the season with a disappointing 72 per cent tackle success rate. When he partnered Mats Hummels in 2013-14, this was at 89%.
The low point of his season came against Schalke as Dortmund's fierce local rivals came back from 4-0 down to secure a draw. With Dortmund still leading late in the game, Sokratis looked to waste time by faking injury. He was involved in a tussle with Yevhen Konoplyanka, but rather than fall down on the ground off the pitch where the incident happened, he ran back onto the field before going down holding his chest.
If he remained off the field, play would not have been stopped, but as he returned to the pitch, medical staff came on to treat him and further wind down the clock. However, Schalke had other ideas, and Naldo scored in stoppage time to seal a famous point. Sokratis's acting skills were sarcastically praised after the game, but his performance was not as BVB let a comfortable lead slip thanks to poor defending and unnecessary mistakes.
Sokratis was once one of Europe's best defenders, but has seen his performances decline in recent years, and will be 30 years old by the time he lines up for his Arsenal debut. He might be the philosopher they need in the dressing room, but if he delivers under-par performances he could prove poisonous on the pitch.