A good-hitting catcher, Koenig played 22 seasons in the Eastern Missouri Baseball Association, primarily for the communities of St. Paul and St. Peters. He was selected to ten EMBA all-star teams.

In the 1970s, he was a catcher for St. Dominic High School in O'Fallon, Missouri.

In the 1980s, he played for Columbia College in Columbia, Missouri.

Koenig managed the O'Fallon American Legion Post 388 team in 1999 and 2000, and then again from 2003 to 2014.

He coached the American Legion Post 218 team in Washington, Missouri from 2016 to 2018.

He was a baseball coach at Lindenwood University from 2012 to 2015.

He is currently in his second year as an assistant baseball coach at DeSmet High School.

In 2015, Koenig was inducted into the St. Charles County Amateur Sports Hall of Fame.