Sometimes the impact a player has on a club, not just the squad, is measured far beyond the realms of just the pitch itself.
Sometimes there is someone within the squad who both embodies the ethos of what the club preaches and stays true to the core values that have been instilled from the get-go.
Sometimes you'll get a player who strengthens a dressing room without ever kicking a ball.
Sometimes, while never being the most naturally talented footballer, the sheer desire and dedication to improving both you and those around you will result in a career far more successful than your own raw ability should have permitted.
Sometimes we'll come across someone like Per Mertesacker. A man whose impact on Arsenal as a whole is far more profound than it may appear at first glance.
Brought in by Arsene Wenger shortly after the demoralising and crippling humiliation the side suffered during that 8-2 defeat against Manchester United, Mertesacker's assignment was clear: sort this lot out. Most likely in far harsher terms.
But that never meant that he had to simply boost the quality of the defence. While that certainly fell within the parameters of his assignment, the German was always brought in to do so much more. His job was to unite, assert, settle and improve the squad from back to front. Moreover, his assistance was needed from top to bottom.
William Gallas, Mikaël Silvestre and Gaël Clichy had all departed in the previous 12 months, and while 66% of those departures were welcome, it meant a lot of experience had walked out of the door.
Stepping into the fold was a German international with plenty of that. His experience was truly invaluable.
Just on first viewing he appears like the model centre-half. He's a giant, after all, and someone whose reading of the game and leadership qualities shine through even from a just a brief glance his direction. For five seasons in north London, he was all of that and more.
Quickly establishing himself as a fan favourite with his vocal, dominant and aggressive style of defending, he never shied away from giving his teammates an earful. His aerial prowess was clear, and he read the game effortlessly.
It's no secret in mentioning that he had deficiencies in his game though. He wasn't the ball-playing sub-genre of defender, one to link defence and attack with a marauding run forward, nor was he the most mobile. The joke that 'milk turns quicker than Per Mertesacker' was a constant jibe, and it would be wrong to suggest his lack of pace didn't catch him out on a number of occasions.
But while his natural ability was not in the world-class bracket, Mertsesacker's professionalism and attitude certainly were.
Under Wenger's guidance, the German was the embodiment of his manager's philosophy. His approach to hard work and self-improvement meant his game was always elevated, but keeping a watchful eye on those around him to ensure similar progress was achieved.
In many ways, Mertesacker could be seen as the Frenchman's number two. He was a shoulder to lean on for fellow struggling teammates, an experienced mentor for the young players and an upstanding, intelligent and respected human being outside of football.
He always conducted himself with the upmost grace and decorum, never speaking ill of another person or club.
But all that may seem like a discounting of his impact on the pitch. His role off it and the manner with which he upheld the values of Arsenal may be the everlasting legacy he left behind, but Mertesacker was fundamental in the Gunners lifting silverware for the first time in 3,283 days.
He came up with the crucial late equaliser against Wigan in their 2014 FA Cup semi-final, and maintained order in the final against Hull City with the Gunners rocked after their early two-goal setback. The pressure facing Arsenal in that final was immense. It's been spoken about since, but Mertesacker's level head on the day proved to be the calming presence that would springboard the side to glory.
One year later and he'd have his say again, this time netting the third goal of their FA Cup final victory over Aston Villa - as captain - to end the clash as a contest.
But if ever you needed a better example of his character, look no further than the 2017 FA Cup final.
Injury had plagued the 2016/17 season for Mertesacker, but as was evident with his stature among this squad and admiration from all those at the club, he was still named captain following Mikel Arteta's (whatever happened to him?) retirement at then end of the previous campaign.
He didn't make a single start all season due to his fitness issues, only making a brief cameo on the final day of the season at home to Everton. While that would be the eventual downfall of the Wenger era at Arsenal - with the Gunners missing out on the Champions League for first time in 20 years - another FA Cup final beckoned.
Laurent Koscielny's red card on the final day of the Premier League season - alongside
Shkodran Mustafi and Gabriel's injuries - meant Mertesacker's inclusion was inevitable for their Wembley showpiece against Chelsea.
What wasn't inevitable, however, was the performance he would put in. In matches like these experience is the vital framework for any level of success, but with just 37 minutes of football under his belt all season, many claimed the writing was already on the wall - especially since Chelsea secured the league title just a few days before.
Instead, Mertesacker produced his greatest performance in an Arsenal shirt. With a cloud of uncertainty filled with concerns over match fitness, age and agility hovering above his head prior to kick off, he towered above it all.
In his reading of the game, protection of Rob Holding, tackling, positioning, leadership...the lot. He was flawless. If ever there was a captain's performance, that was it.
Arsenal's attacking prowess throughout was superb, but the gigantic defensive foundations put in place by Mertesacker were the platform for success. It's been aptly named the 'Per Mertesacker Final' by Gunners supporters.
“I’m just humbled by the trust in my ability, in my person, of the manager, my teammates,” he said. “I could never feel any doubt that I’m probably not capable even with the background I came in with.
“What stood out was the trust in me that I could still bring it on final occasions, at Wembley. Then when it really counts you cannot afford to make mistakes. I was amazed by that trust of the whole club in me personally."
His fellow teammates had trusted in him because he had ingrained that very same sense of belief into each and every one of them from the moment he set foot through the door.
A man with so much more to offer than just a steady head and an experienced pair of feet on the pitch, it came as little surprise that Mertesacker's Arsenal affiliation didn't end after his retirement. As head of the academy, he has the position with which to maintain and build on the philosophy Wenger worked so hard to imprint on the club - as a figure who youngsters will look up to and respect.
While his new goal may have been born out of gratitude to his former mentor, there was never any doubt that the World Cup winner was going to do anything other than teach and guide. It's in his blood, and Arsenal were major benefactors of him during his time in north London.
Through his loyalty to the club and adherence to the 'Arsenal way' he earned himself an affectionate name from his supporters. But....
He was so much more than just a Big F---ing German.
Source : 90min