Štimac started his professional career with KK Kvarner of the Croatian HT Premijer liga in 2001.
Štimac began his coaching career in 2017, as an assistant for Fribourg Olympic in Switzerland, serving under Petar Aleksić.
[5] After Otten was fired after a disappointing start of the season, Stimac signed a contract as head coach until 2023–24 on October 31.
[6] Štimac and Donar reached the finals of the Dutch playoffs, following a win in the semi-finals over Heroes Den Bosch.
[7] On December 3, 2024, Štimac was sacked by Donar, following a disappointing start of the season in which the club was ranked 17th in the BNXT League.