Formerly the club's head of football, Sanllehi's exit means managing director Vinai Venkatesham will sit at the top of the new hierarchy, with head coach Mikel Arteta and technical director Edu to make the footballing decisions.
Here, the PA news agency takes a closer look at the work Arteta and Edu have ahead of them in the coming weeks.
A new deal for captain and talisman Pierre-Emerick Aubameyang is key for Arsenal – especially given the forward could leave for free next summer. The PA news agency understands a contract agreement is in place and an announcement could be made by the end of the week. Making sure they retain the services of such an important part of Arteta's side will be a boost for the coming years and show potential new recruits that the club mean business.
A case for the defence
Speaking of new recruits, Arteta said towards the end of last season that signing a defender will be important given the number of injuries he has in that position. Pablo Mari, Calum Chambers and Shkodran Mustafi all missed the FA Cup final win over Chelsea and, while William Saliba has now linked up with the first team following a season on loan at Saint-Etienne, Arsenal are likely to bring in more reinforcements. Lille's Gabriel Magalhaes has been strongly linked with a move to the Emirates Stadium, with the likes of Malang Sarr and John Stones outside bets, while strengthening midfield options is also high on the agenda.
The Ozil poser
Despite being the highest-paid player in the club's history, Mesut Ozil has fallen out of favour in north London. The 31-year-old did not feature for Arteta's side since the season restarted following the halt due to the coronavirus pandemic. Despite that, Ozil insisted last week in an interview with The Athletic that he will decide when he leaves the club – but can Arteta and Edu find a solution that either brings the former Germany international out from the cold or clears at least some of his salary from the wage bill?
Clear the decks
While supporters will quite rightly be focused on incomings this summer, Arsenal also have a number of players they need to offload – if only to balance the books. The likes of Sokratis Papastathopoulos, Lucas Torreira, Ainsley Maitland-Niles and Mohamed Elneny could all find themselves plying their trade elsewhere next season if the right offers come in. Then there is the future of Matteo Guendouzi, who has not been selected in a matchday squad since a post-match incident in June's defeat at Brighton led to further-reaching questions about the midfielder's mentality.
Bernd Leno came second only to Aubameyang in Arsenal's official player of the year poll for the 2019/20 season. But his place as Arteta's first-choice goalkeeper heading into the new campaign is by no means certain following the fine form of Emiliano Martinez, who stepped in when Leno was injured at Brighton. The Argentinian excelled having finally been given his chance and the tough call on who will don the gloves is one that will have to be made – with the potential for the one who misses out to push for a move before the transfer window closes on October 5.