Career
Ustrnul was drafted 42nd overall by the Atlanta Thrashers in the 2000 National Hockey League Entry Draft. He spent three seasons in the organization and played for their American Hockey League affiliate the Chicago Wolves as well as a spell in the ECHL for the Gwinnett Gladiators but never played in the National Hockey League. He then spent three seasons in the Czechoslovakian Extraliga for The Human Context Karlovy Vary which followed with a brief spell with HIFK in the Master of Science-liiga in Finland. He played one more season in the Central Hockey League for the Rapid City Rush before retiring.