Despite impressive form for Celtic last season, the former captain of Croatia's U21 side never received a senior call-up. This, along with a lack of communication during his period out of the game with a broken knee in 2016 left Simunovic frustrated with the Croatia FA.
Simunovic said: 'When I was injured for a long time, no one from the Croatia FA called me. No one asked about my health.'
'Yet I had played nearly 50 games for the younger Croatian international teams and had been captain of the Under-21s.'
The centre-back made the decision to switch allegiances after speaking with close members of his family.
He said: "My parents and my grandparents are all from Bosnia and Herzegovina. I was contacted by national coach Mehmed Bazdarevic and came to the definite decision I wanted to play for him and Bosnia and Herzegovina."
"I then spoke to all my family and decided to play for my country."
Simunovic will join the Bosnia squad for the upcoming fixtures against Gibraltar and Cyprus.