[12] On 20 October, he made his league debut for Charlton, coming off the bench as a second-half substitute in the side's 1–0 win over Blackpool.

[23] On 16 April, he scored his first Champions League goal in a 4–2 win against Atlético Madrid in the quarter-finals second leg, helping his team progress to the semi-finals.

[24] Borussia eventually reached the final, where Maatsen started the match and made a misplaced pass that led to Real Madrid's second goal in a 2–0 defeat at Wembley Stadium.

[29][30] On 17 August 2024, Maatsen made his Aston Villa debut as a substitute in a 2–1 opening day victory over West Ham United.

[32] In September 2023, he received his first call-up to the Netherlands senior team by head coach Ronald Koeman, for two UEFA Euro 2024 qualifying matches against Greece and the Republic of Ireland.