Arsenal confirmed last month that the 26-year-old's contract had been terminated by mutual consent, making him a free agent after 17 years at the club. That freedom to negotiate outside the transfer deadline ultimately paved the way for a return to De Kuip, where Nelson was a fan favourite under then-manager Arne Slot.
Nelson leaves Arsenal having made 90 first-team appearances, scoring eight goals and adding nine assists, a return built largely on a series of loan spells away from the Emirates. He never fully established himself as a regular starter in north London, making just 15 starts across 61 Premier League appearances for the club.
Last season he was loaned to Brentford, contributing a goal and two assists in 14 competitive appearances for the Bees having previously spent time at Fulham and, before that, at Hoffenheim in the Bundesliga during the early stages of his career.
It is the Feyenoord chapter that remains the highlight of his development away from Arsenal. During the 2021/22 campaign, Nelson scored four goals and provided seven assists in 32 appearances as the Rotterdam club reached the final of the inaugural UEFA Europa Conference League, with his form that season earning widespread praise in the Eredivisie.
There had been earlier interest from West Ham United, who explored a deal worth around £3 million before stalling on the move, giving Feyenoord the opening they needed to bring Nelson back on a free transfer instead.
Nelson joined Arsenal's academy at the age of eight and progressed through the Hale End setup before signing his first professional contract in December 2016, going on to make his senior debut in the 2017 Community Shield.
Among the highlights of his time at the club was a stoppage-time winner against Liverpool at the Emirates during the 2019/20 season, while he also won the FA Cup in 2020 and featured in Community Shield victories in 2017 and 2020.
The move gives Feyenoord fresh competition in wide areas as they continue their pursuit of domestic honours, with Nelson expected to add Premier League experience and pace to a squad already building depth for a season that will include European commitments.