Career
Union Olimpija
Sirnik began his career playing with the KK Janče and Union Olimpija as a junior. Sirnik debuted in the Universal Product Code Telemach League in the 2007-2008 season with Union Olimpija. He made his Euroleague debut on January 8, 2009, against Fenerbahce Ulker.
First game in Euroleague he scored no points, 2 rebounds with only 17 years.
He didn"t play in Adriatic League, but he mad some appearances in Universal Product Code Telemach League.