Kolmanič joined ATXFC in March 2021 and has since recorded six (6) assists in 57 total appearances (41 starts) for the Verde & Black. Prior to arriving in Austin, he spend the 2017-2021 seasons with NK Maribor in his native Slovenia. He made 45 appearances (43 starts) and contributed six (6) assists across all competitions with Maribor, helping the club capture the 2018-19 PrvaLiga title. Kolmanič also made seven (7) starts in the UEFA Youth League with the NK Maribor U-19 side.
At the international level, Kolmanič was called up to the Slovenian senior men's national team for the first time in October 2021, and made 39 combined appearances with the U-21, U-19, U-18, U-17 and U-16 Slovenian National Teams.
