Curley of Of Mice and Men?

i watched the movie today at school and the actor in the movie actually had some skills on the speed bag. He played a character that was best welterweight in the world, won the golden gloves and all that. my question is, for the people that seen it, is that guy a boxer in real life? If so, how was his career? His name is Casey Siemaszko Trivia Brother of Nina Siemaszko Brother of Corky Siemaszko, a reporter/writer for the New York Daily News. Son of a Polish underground fighter who survived the Sachsenhausen concentration camp. His last name is pronounced "Shye-mash-ko." Has a yellow belt in the martial art Hapkido Went to and graduated from the Goodman School of Drama at Depaul University in Chicago, which his sister Nina later attended along with another alum Gillian Anderson.