Anderlecht in 2024. Debast is a youth product of
Anderlecht, signing his first contract in October 2019. He made his professional debut on 2 May 2021, in a 2–2
Belgian First Division A draw against
Club Brugge. On 11 June 2024, during an interview for
Het Laatste Nieuws, Debast confirmed that he had agreed personal terms to join Portuguese side
Sporting CP from the
2024–25 season.
Sporting CP . On 4 July, Debast signed a five-year contract with
Primeira Liga side
Sporting CP, for a fee of
€15.5 million, plus €5.5 million in add-ons, and a 15% sell-on clause in favor of Anderlecht. On 7 August, he made his debut for the club, where he committed two errors, that led to
rivals Porto first and second goals in their 4–3 loss in the
2024 Supertaça Cândido de Oliveira. This resulted in him losing his starting spot, however, on 17 September with regular starter
Eduardo Quaresma being sidelined with a knee injury, Debast was entrusted back to the starting eleven, scoring his first goal for the club, and the first goal of his career, by netting a shot from outside the box in Sporting's 2–0 victory over
Lille during the inaugural matchday of the newly formatted
Champions League league phase. ==International career==