Having been a youth team player at Anderlecht, Trésor made his Eerste Divisie debut for NEC on 21 September 2018 in a game against Helmond Sport, as a 78th-minute substitute for Jonathan Okita.

Trésor had hit double-figures in assists for the 2022–23 season by mid-October as part of Genk's impressive winning run, making him the highest-assist maker in the top-10 ranked European leagues.

[7] Despite this, Trésor was not named by Belgium national team coach Roberto Martinez in the preliminary Belgian squad of 55 ahead of the 2022 FIFA World Cup, and did not make the plane for Qatar.

[8] A continuation in strong form saw big calls for Trésor and team-mate Bryan Heynen to be capped by new national team coach Domenico Tedesco for his first games in charge against Sweden and Germany in March 2023,[9] but neither player was chosen.

Tresor was voted Belgian Footballer of the Year at the Pro League Awards, and also won the 2023 Ebony Shoe for best player of African extraction in the league, holding off Gent's Gift Orban, Victor Boniface of Union Saint-Gilloise and Tresor's own Genk team-mates Joseph Paintsil and Bilal El Khannouss to both awards.