In 2007, Picak started playing for the Croatian national under-15 football team, and also made his debut for the country's under-17 national team during the same year. In 2010, he was promoted to the country's under-19 national team. Up to date, he won a total of 33 international caps for the Croatian national football teams at the under-15 to under-19 levels. On 11 August 2013, due to
Danijel Subašić's injury, Picak was called up as a replacement, by
Croatia's head coach
Igor Štimac for a friendly match against
Liechtenstein on 14 August 2013. ==Coaching career==