It looked at one point as though Pierre-Emerick Aubameyang would be the talisman of the club, but now he is the symbol of a troubled period.
The aim of the new three-year contract signed by the forward was to leave a legacy at the club. His legacy is more complicated than anyone could have imagined.
A gradual decline in his relationship with Arteta led to him becoming adrift. After being ostracised and punished, he was allowed to join Barcelona on a free transfer in February, but only after he was sacked by one of his former employers, Thomas Tuchel.
With a 10-point gap between the two sides, the 33-year-old will face Arteta and the team it was felt would grow better without him. There are still marks from that time. The tattoos are done in a certain way. Such was the depth of feeling and the speed of transformation that this weekend will likely see him wear a shirt with a tattoo on his arm.
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Body art was a point of contention at the end of his career. According to sources, there wasn't one big incident which prompted the club to part with the player, more a series of small incidents which undermined the professionalism Arteta was demanding from his squad.
One source said that the player missed a drug test, turned up late for meetings and asked for time away from the group. There was a view inside the club that he wasn't showing enough dedication while he was on compassionate leave to visit his sick mother. His flash cars and garish lifestyle can be divisive, especially for those who value humility and discipline, but he is seen as a popular character.
Arteta was ruthless when it came to coming to an end. After being stripped of the captaincy, he was allowed to leave on a free transfer. He was upset. Recently, footage from his early days at Barcelona was leaked.
He is unable to deal with big characters and big players. He needs some young players who are quiet.
"I still had a lot of bad feelings in me, and I wish all my old guys well, just not on Nov. 6," said the former player.
Aubamayeng was allowed to leave at a high cost. The lack of a replacement and the fact that Eddie Nketiah and Alexandre Lacazette were the only replacements, meant that the club missed out on a place in the group stage.
The club believed the long-term cultural shift Arteta had implemented was worth the short-term risk and this season, after a summer of shrewd investment, that view is reaping dividends. The difference between Gabriel Jesus and Pierre-Emerick Aubameyang is that Jesus presses relentlessly, generating space and chances for others.
Jesus' seven-game goalless streak is a concern, but his contribution to the team outweighs it. The contribution was mostly measured in goals. A key reason why he was given a lucrative contract later in the year was that he was the fastest player in the history of the club to reach 50 goals. He scored 13 goals in 43 league games after he signed that deal. This made it easier for some fans of the club to accept the departure of the forward.
Arteta was never fully sold on the idea of resurrecting him playing through the middle as opposed to off the left wing, despite the fact that he had been at his best off the left wing. He is expected to start as a center-forward on Sunday.
After a turbulent year, working with Tuchel again would have been great. In the midst of the row with Arteta, Tuchel spoke glowingly of the relationship he had with Pierre-Emerick Aubameyang, the player who scored over 80 goals in 95 appearances for the German club.
Potter has spoken glowingly of the attitude of the player, particularly in reference to his recovery from a horrifying robbery at his family home in Barcelona, which left him with a broken jaw. Potter will be looking for a response from his players after a defeat at his former club.
The line of forwards aiming to break the "No. 9 curse" at the club has been around for a while. Two years ago, sources have told ESPN that the Blues were interested in signing the Frenchman, but he chose to stay with the club. He has a chance to remind people why he was so in demand.