After graduating he returned to Berlin and played for the local senior team. In the mid '60s he was selected for the US men's national ice hockey team. Though he was on the roster, he did not play at the 1965 Ice Hockey World Championships, but did appear in four games the following year. The team finished in a disappointing sixth place, and he was not retained for future teams. His final official appearances came in 1969 for the Rochester Mustangs, but after two poor outings Blackburn called it a career.