Salah-Eddine's youth career started with
Jong Ajax in 2018. On 1 August 2022, he signed a contract extension until the end of the 2025 season. He then joined
Twente on loan for the
2022–23 season. On 1 February 2024, he joined Twente on a permanent deal until 2027. On 3 February 2025, Salah-Eddine joined
Serie A club
Roma. On 31 August 2025, Salah-Eddine returned to the Netherlands and joined reigning champions
PSV, on an initial one-year loan with an option to buy. ==International career==