Messner enters his third season as the assistant coach for the Tomcats men's lacrosse team in 2018-19. He currently serves as the defensive coordinator and specialties coach.
Under Messner, the 2017 Tomcats tied the program record for wins in a season (10) and reached the ORLC Championship Tournament Semifinals. A program record 10 Tomcats earn all ORLC awards in 2017.
Before arriving at Thiel, Messner coached high school lacrosse and was a four year member of the men's lacrosse team at Wheeling Jesuit University earning degrees in criminal justice and business in 2016.