Sven Mislintat will finish work as Arsenal's head of recruitment on Friday after 14 months in the job, but what has his impact been and what comes next for the club?
Since the German arrived from Borussia Dortmund in November 2017, the Gunners have signed nine players across three transfer windows with a net spend of £78.4m.
In his first window, Mislintat brought in Pierre-Emerick Aubameyang from Dortmund, where he first signed the Gabon striker from St Etienne, as well as another former Dortmund player in Henrikh Mkhitaryan from Manchester United and little-known Greek defender Konstantinos Mavropanos from PAS Giannina.
Together with the now departed chief executive Ivan Gazidis and current sporting director Raul Sanllehi, who joined from Barcelona, Mislintat was then part of the three-man panel that appointed head coach Unai Emery to succeed Arsene Wenger in May last year.
In Mislintat's second window, the club signed central midfielders Lucas Torreira and Matteo Guendouzi from Sampdoria and Lorient respectively, while Sokratis Papastathopoulos was another player brought in from Dortmund. Stephan Lichtsteiner joined from Juventus on a free transfer, and Bayer Leverkusen's Bernd Leno arrived as the long-term successor to goalkeeper Petr Cech.
During the most recent January transfer window, Mislintat's departure was announced by the club as the Gunners appeared to miss out on targets Ivan Perisic and Yannick Carrasco, but Arsenal did sign Barcelona's Denis Suarez on loan.
Who is he?
Sky Sports News have spoken to a number of people who have known and worked with Mislintat for some time; he is described as quiet, friendly and highly-motivated with fantastic technical scouting skills.
He has been nicknamed 'Diamond Eye' since his time at Dortmund, having spotted a number of players that have become huge stars in the game such as Ousmane Dembele, who is now at Barcelona.
Profiling players and picking the right targets seems to be his speciality, rather than negotiating contracts, and he was less interested in working with the talent once they were through the doors of the Emirates Stadium, preferring to keep a low profile and continue working under the radar to find the next gems.
Why is he leaving?
It has been suggested to Sky Sports News that some differences of opinion with Spanish sporting director Sanllehi is just one of the reasons for Mislintat's departure, as well as a level of frustration over Arsenal's lack of financial firepower in the market. Arsenal were linked with some big-name players in the January window such as Perisic and Carrasco, but were only in a position to propose loan deals.
The kind of person Arsenal are looking for to replace Mislintat also suggests he was not the right fit for the north London club's way of working, with a new personnel structure that includes Sanllehi and Hussein Fahmy having been phased in since the departures of Wenger, his chief negotiator Dick Law and chief scout Steve Rowley.
What next for Arsenal?
Sky Sports News have been told the Gunners are looking for more of a technical director to fill Mislintat's shoes; someone not only able to identify the next best talents but also help nurture them once they are at the club with a more closer tie to Unai Emery and the coaching staff.
The club would like someone who is willing to be more hands on - a 'face' for the recruitment side if you will - who can travel with the team, take an integral part in club meetings and perhaps even do the odd interview.
A comparison with Eric Abidal - the sporting director at Barcelona - has been made to Sky Sports News; an ex-player who can help bridge the gap between dressing room and boardroom.
Significantly, ex-Arsenal star Marc Overmars has done an excellent job in this role at Ajax since 2012. As their technical director, he has helped to identify, sign and develop players such as Davinson Sanchez, Matthijs de Ligt, Patrick Kluivert's son Justin and Frenkie de Jong, who will sign for Barcelona in the summer.
The renowned Roma sporting director Monchi is another name that has been mentioned - and someone who has helped keep Roma among Europe's top clubs on a tight budget, by bringing in talented youngsters and turning them into marquee players.