Mertesacker started the job in 2018 and helped players such as Myles Lewis-Skelly, Ethan Nwaneri and Max Dowman advance to the first-team squad during his tenure.
The former defender was offered the role by past manager Arsene Wenger and Ivan Gazidis during the final year of his playing career. He spent 12 months learning the ropes before taking on the job full-time in what has been a successful stint.
Why is he leaving?
Speaking to the club website, he explained that he is ready for something new after almost a decade helping the next generation.
“Arsenal is and will always be a very special club to me, so this was a difficult decision. I am very thankful for the trust the club put in me when transitioning from a first-team player directly into the role as Head of Academy. Now it is time for me to move on and explore something new and push myself even further.
“I remain focused on finishing the season strongly, continuing to nurture and develop our young talent and support a seamless transition until my very last day with the club."
Arsenal wave goodbye to a legend
Richard Garlick, Arsenal’s Chief Executive Officer added: “We support Per’s decision to pursue something new, but we will be incredibly sad to see him leave at the end of the season.
“We were fortunate to have retained Per as Academy Manager once he finished his playing career with us in 2018. He understands what Arsenal stands for and this has been a constant in his leadership - inspiring our Academy coaches, staff and young players in an Arsenal way and giving so many an opportunity to develop and shine.
“We’re happy that Per remains in role until the end of the season whilst we focus on our succession plan.
“We continue in our pursuit of winning major trophies with a sustained focus and investment in our Academy.”
The appointment of a new academy manager should come at the end of the season as the club prepare for what is a huge change staffing change behind the scenes.