[2] He rose through the ranks and became the youngest player to sign a professional contract with the club, aged 15 years and 11 months.

[5] He left the club before making his debut in an official match, joining the youth ranks of Genoa in Italy in January 2012.

After missing out on the first half of the 2015-16 season due to injury to his right fibula,[10] Simić was supposed to join Hajduk Split in a six-month loan deal in January 2016.

[15] On 28 June 2019, Simić joined Croatian First Football League club Hajduk Split on a free transfer.

[17] Simić chose to represent Czech Republic while having the possibility to play for Croatia, Serbia and Bosnia and Herzegovina, from which his parents came from, his father's ethnicity and whose passports he holds as well.