[2] Čajić started his professional career at Teplice, before joining Dukla Prague in 2014.
Čajić came through Sparta Prague's youth academy, which he joined in 2007 from a local club.
[9] He helped İstanbulspor achieve promotion in the 2021-22 season for the first time in 17 years.
[10] He started in İstanbulspor return to the Süper Lig in a 2–0 season opening loss to Trabzonspor on 5 August 2022.
[11] Čajić represented Bosnia and Herzegovina on various youth levels.