*Club domestic league appearances and goals, correct as of 07:53, 4 November 2024 (UTC) ‡ National team caps and goals, correct as of 21:43, 16 October 2024 (UTC)
Hien played youth football for AIK, where he played alongside future professional players Alexander Isak and Leopold Wahlstedt.[1] In 2016, he signed with Vasalunds IF with which he made his senior debut in Division 1 Norra in 2017.[1] Up until the age of 21, he operated mainly as a striker, but was convinced to switch to centre-back, and flourished in that new position.[1]
On 27 August 2022, Hien joined Italian club Hellas Verona on a permanent deal, signing a four-year contract.[2]
Atalanta
On 2 January 2024, Hien joined Serie A side Atalanta, signing a contract until June 2028.[3][4] The transfer commanded a reported fee of €9 million.[4]