Mastouri began playing football in the amateur
Tunisian Ligue 3 with
AS Degache in 2016. In 2020, he had a short stint with
LPS Tozeur. This led to a move to the
Tunisian Ligue Professionnelle 1 side
ES Métlaoui in 2021 where he stayed 2 and a half season. On 26 September 2023, he moved to the
Iraq Stars League team
Al-Najaf FC where he scored 10 goals. On 15 August 2024, he transferred to
US Monastir on a 2-year contract. On 17 August 2025, Mastouri signed with
Russian Premier League club
Dynamo Makhachkala. ==International career==