After returning to AZ from his loan, Reijnders was named to the Eredivisie Team of the Month in September 2022 and April 2023, before signing for Italian giants AC Milan in the summer of 2023.

[4] Afterwards, Reijnders returned to AZ and became part of the first team, in which he managed to play in the 2022–23 Europa Conference League semi-finals.

[7] On 11 November, in a Serie A match against Lecce at Stadio Via del mare, Reijnders scored his debut goal for Milan.

[13] Reijnders is a mobile central midfielder with the penchant for going forward into the final third and the opposition's penalty area, to either make attempts at scoring or to press opponents.

Upon his transfer to Milan, he was immediately integrated into the team's starting XI by manager Stefano Pioli as a left-sided central midfielder, known as mezzala in Italy, in a 4–3–3 formation.