Mustafić started his professional career at Sarajevo, who loaned him to Slovan in 2020. Later that year, after signing permanently with the Slovak side, he was sent on loan to Nitra. In 2023, he joined Danish side OB, and spent the first half of 2024 on loan at Polish club Śląsk Wrocław.
Club career
Early career
Mustafić started playing football at his hometown club Sloboda Tuzla, before joining Sarajevo's youth academy in 2015.[2] He made his professional debut against Radnik Bijeljina on 25 February 2018 at the age of 18.[3] On 15 September 2019, he scored his first professional goal in a triumph over Zvijezda 09.[4]
In January 2020, Mustafić was loaned to Slovak side Slovan Bratislava until the end of season, with an option to make the transfer permanent, which was activated in July. In August, he was sent on a season-long loan to Nitra.[5]
On 12 January 2024, after spending the previous year with Danish side OB, Mustafić joined Polish club Śląsk Wrocław on loan until the end of the season.[6] After finishing his loan spell, Mustafić returned to OB.[7]
On 22 July 2024, Mustafić returned to Slovan Bratislava on a three-year contract.[8]