When Mesut Ozil joined Arsenal from Real Madrid in 2013 he was widely considered among the best players in the world and quickly established himself as a key component in the Gunners team.
Under Arsene Wenger, the World Cup winner helped the North London outfit to three FA Cups and was named the club's player of the season in 2015-16 as they finished second in the Premier League.
However, he has endured an alarming downturn in fortunes at the Emirates in recent seasons, with below-par performances and off-field issues contributing to a somewhat toxic experience for the German.
He has publicly butted heads with the club on a number of occasions in the past few years and has been effectively ostracized as a result, with Mikel Arteta removing him from the official squad list for 2020-21.
Ozil's transformation into a pariah at Arsenal has been a gradual process, with a number of notable incidents helping to accelerate the decline in relations between player and club.
Arteta said: "I tried my best, I tried to give him as many opportunities as I could... I've been patient, given him opportunities and been fair."
Here, Goal looks at some of the possible reasons why the playmaker the club once broke their transfer record to sign is no longer playing for Arsenal.
Like many footballers, Ozil has not been shy about using his platform to speak out about issues he feels warrant amplification, but unfortunately for him, his causes have generated a lot of controversy.
It is often said that politics and sport don't mix. The reality, however, is that politics is everywhere but if a sportsperson gets involved or associated in some way, they may find themselves walking a tightrope.
Ozil's friendship with Turkish President Recep Tayyip Erdogan, who was 'best man' at his wedding, has prompted criticism from many quarters, particularly in Germany - something the player made specific reference to when confirming his retirement from the Germany national team in 2018.
His personal relationship with Erdogan may not have had a major effect on his Arsenal career, but his efforts highlight the treatment of Uighur Muslims in China have certainly caused ructions.
A diplomatic incident occurred in late 2019 when Ozil used his Instagram page to speak out about the plight of the Uighur Muslim population.
The reaction in China was not favourable and the state broadcaster removed Arsenal's subsequent match against Manchester City from their schedule. Arsenal immediately strained to make it clear that Ozil's comments were made in a personal capacity and did not reflect the club's views.
“Regarding the comments made by Mesut Ozil on social media, Arsenal must make a clear statement," a post on the Chinese social media site Weibo read.
“The content published is Ozil's personal opinion. As a football club, Arsenal has always adhered to the principle of not involving itself in politics.”
Ozil's statement after being axed from the Arsenal squad suggests that his outspokenness on political issues is indeed a problem for some within the club, but he remains steadfast in his defiance.
"I can promise you that this hard decision won't change anything in my mindset," he said. "I will continue to train as best as I can and wherever possible use my voice against inhumanity and for justice."
Refusal to take a pay cut
The optics of Ozil refusing to take a voluntary pay cut to his £350,000 a week salary in the middle of the Covid-19 pandemic were not flattering but the player is confident that he did the right thing.
Either way, it is likely that standing up to the club on the matter would have ruffled more than a few feathers.
"People who know me know exactly how generous I am and, as far as I’m aware, I was not the only player who rejected the cut in the end, but only my name came out," Ozil said in an interview with The Athletic.
"I guess that’s because it is me and people have been trying for two years to destroy me, to make me unhappy, to push an agenda they hope will turn the supporters against me and paint a picture that is not true.
"Possibly the decision affected my chances on the pitch, I don’t know. But I’m not afraid to stand up for what I feel is right - and when you see what has happened now with the jobs, maybe I was."
The Gunnersaurus incident
In what has become a battle for hearts and minds, Ozil landed a significant blow to Arsenal when he offered to cover the wages of the person who worked as the club's mascot Gunnersaurus.
Jerry Quy, whose job was to don the famous dinosaur suit on matchdays, was made redundant by the club, along with many others, as a result of the Covid-19 pandemic but Ozil stepped in on hearing the news.
"I was so sad that Jerry Quy aka our famous & loyal mascot Gunnersaurus and integral part of our club was being made redundant after 27 years," the Arsenal midfielder wrote on Twitter.
"As such, I’m offering to reimburse Arsenal with the full salary of our big green guy as long as I will be an Arsenal player."
The optics of the scenario are not particularly flattering for Arsenal, particularly when the club, like many others at the highest level are able to find millions for transfer fees and player contracts.
Ozil's public offer will not have gone down well because it will have dipped in to a well of resentment that is felt by some supporters - and ex players.
I was so sad that Jerry Quy aka our famous & loyal mascot @Gunnersaurus and integral part of our club was being made redundant after 27 years. As such, I’m offering to reimburse @Arsenal with the full salary of our big green guy as long as I will be an Arsenal player... pic.twitter.com/IfWN38x62z— Mesut Özil (@MesutOzil1088) October 6, 2020
Former Gunner Paul Merson said that Ozil's move - which was branded a "PR stunt" by another ex-Gunner Ray Parlour - "made Arsenal look absolutely stupid".
"Binning their mascot just shows how selfish and out of touch the people who run the club are these days," Merson told The Daily Star. "You cannot believe how angry I am about this. It is unbelievably shocking at the highest level.
“Arsenal used to ooze class. I don’t think the owners even know what that word means any more. Whoever made the decision to get rid of the mascot needs to take a long hard look at themselves.
“The guy in the suit, Jerry Quy. This bloke loves doing that. He was there when I played for Arsenal. He’s an institution. My kids grew up with him. They would be as interested in the dinosaur as they were in the players. Their faces would light up.
“It absolutely does my head in that they’ve got rid of him just to save money. How many other clubs, ones in the lower leagues who are really struggling, have done that? Even if they bring him back when fans are allowed back in the stadium, it’s a disgrace.”
Merson added: “They’ve just signed Thomas Partey for £45m. If he’s on £150,000-a-week, are you telling me they couldn’t have offered £149,000 and given the rest to the dinosaur?"
There is an argument to be made that Ozil simply does not merit a place in the team and it is true that his performances have been well below the standards expected of a World Cup winner.
Having regularly chipped in with plenty goals and assists each season - a highlight being the 2015-16 campaign when he contributed 19 assists and six goals in the league - his form dipped in the last two years.
He had a hand in seven goals in the Premier League (five goals, two assists) in 2018-19, which was a sharp drop off and it worsened to just three goals (one goal, two assists) in 2019-20 as game time dried up.
Former Arsenal head coach Unai Emery suggested that Ozil was not particularly suitable for a high-pressing game, telling BBC Sport in 2019: "He has talent that allows other players to be better, but when you want a bit more aggressive pressure he does not have the best qualities for that."
The issue of attitude has been remarked upon by former Arsenal boss Unai Emery, who claimed that Ozil did not demonstrate the requisite levels of commitment.
Emery took over the reins at the Emirates after Arsene Wenger's departure and, while he was an admirer of the player's ability, he was not so impressed by his application.
“I tried my utmost to help Ozil. Throughout my career, talented players have been my favourites and they have played at their best or close to their best with me," Emery told the Daily Mail.
“I was always positive with him in terms of wanting him to be involved, but then the attitude that he adopted, and the commitment levels, well, they weren't enough."
Despite being dropped from the official squad altogether, Ozil has shown his dedication to training in a number of clips where he is training individually on his strength.
Indeed, there are lots of contradictory testimonies regarding Ozil's supposed attitude problems in training and on the pitch, with his team-mates rejecting the reports.
Laurent Koscielny said that Ozil was professional in training, remarking that he was "always on time" for sessions and "undoubtedly at the level demanded" of a Premier League player.
The playmaker's compatriot Shkodran Mustafi has been similarly effusive, saying: "Every time I see him in training he’s doing the best he can.
"He tries to train well and everything else is not in my hands. I’m not the one who makes the decisions."