When Jurgen Klopp held his final speech as Borussia Dortmund coach, he said: "It's not important what people think of you when you arrive. It's important what people think of you when you leave."
When applying those words to Pierre-Emerick Aubameyang, a lot is left to be desired for the 28-year-old, who joined Arsenal on Wednesday . In his four-and-a-half seasons, he developed into a world-class striker, taking over from Robert Lewandowski and scoring a jaw-dropping 141 goals in 213 games. Aubameyang leaves as third-best in BVB's all-time goalscorer list, just 20 goals away from becoming the best the Westfalenstadion had ever seen.
Oddly, he does not leave a legend.
The striker was consistently booed with each of his 19 touches in his final match for the Black and Yellows last Saturday in a disappointing 2-2 draw against Freiburg.
It was the result of the Gabon international using dirty tricks to force the club's hand to sell him, although Dortmund had very much planned to finish the season with their star striker. Aubameyang skipped a team meeting -- which, coincidentally, was about team spirit -- on purpose, which led to his third suspension within two seasons for disciplinary measures.
Sporting director Michael Zorc, who declared his love for Aubameyang and his professionalism last summer, did not recognise the player anymore following the Wolfsburg game in mid-January, which he missed due to suspension.
Overall, it is a great shame that Dortmund and Aubameyang part ways in bad faith.
Since joining from Saint Etienne in 2013, he had been eccentric in his lifestyle, yes, but always a hardworking professional who sustained few injuries. But when fans feel rejected, all the great contributions are quickly forgotten. And Aubameyang only has himself to blame.
Meanwhile, centre-back Marc Bartra, who left the Ruhr side for Sevilla, has been seen off by Dortmund and their fans with a lot of gratitude. Bartra had quickly developed into a fan favourite, as he embraced the Black and Yellow colours without hesitation. His move away from the Westfalenstadion is in many ways a painful one as well. Until the horrific attempt on his life in April 2017 ahead of the Champions League quarterfinal home leg against Monaco, the former Barcelona defender was a regular starter and on the verge of becoming BVB's best centre-back.
This season, the centre-back has struggled -- like all of Dortmund's defenders in a tricky stint under Peter Bosz that left the defence exposed time and time again. Under Peter Stoger, Bartra had fallen down the pecking order, not making the cut for the match day squad in 2018.
Tellingly, Bartra only thanked Thomas Tuchel and Bosz for their trust in his initial farewell message, which he took down and replaced it by a more general "thank you" to the coaches who trusted him.
One can only speculate about the reasons for Bartra's exit, but getting regular playing time in a World Cup year was a huge factor.
Though as much as the transfer window might say about professional footballers and their readiness to play foul to force a transfer, it also speaks volumes about Dortmund being a club without a real plan.
Under interim coach Stoger, the team are still struggling. In 2018, the Black and Yellows managed only three disappointing draws against teams from the lower half of the table. Saturday's 2-2 draw against Freiburg unveiled a dysfunctional team that has far greater problems than just losing its key assets.
Inexplicable lapses in defence that saw the hosts throw away an early lead were followed by abject attempts to find back into the game. The build up play was thoroughly uninspired with the team chemistry looking to be on an all-time low.
All that was accompanied by boos from the Dortmund fans, who usually take pride in supporting their team while atmospheres in Gelsenkirchen or Munich quickly grow hostile toward their own teams.
Now, with a top four finish to qualify for the Champions League looking to be a greater struggle than initially anticipated, Dortmund have to quickly integrate a new striker in Michy Batshuayi, who is set to join from Chelsea on a loan deal until the summer.
BVB can only hope that the 24-year-old Belgian, who brings attributes similar to Aubameyang's, has a bigger impact than Ousmane Dembele's replacement Andrey Yarmolenko, who quickly went off the boil after a promising start and will now miss several weeks due to injury.
Batshuayi could add another dimension to BVB's attacking play, as he can, on paper, link up slightly better with his teammates and has more skills to beat his opponent one-on-one.
Though it is indeed a precarious situation for Dortmund, who had a replacement lined up for Lucas Barrios in Lewandowski, and a replacement lined up for the Pole in Aubameyang. Yet even with Aubameyang uttering his wish to leave the club before last summer, the Westphalians have failed to prepare for a predictable exit and are now scrambling in a tricky situation.
Without knowing who will be leading the lines for the Black and Yellows next season or, in fact, be coaching from the sidelines, the future of Borussia Dortmund is more uncertain than ever.