Deegan joined a Chicago fastpitch softball team for the American Softball Association National Tournament in 1943. She was soon signed by the league to play for the Rockford Peaches. She played for the Peaches until midway through the  season, when she was traded to the Kenosha Comets, beginning a four-year stretch in which she played for six teams.
Deegan joined a Chicago softball team participating in the American Softball Association National Tournament in 1943. Shortly after, she was recruited by the league to play for the Rockford Peaches. She remained with the Peaches until roughly halfway through the season, at which point she was exchanged for the Kenosha Comets, embarking on a four-year period during which she played for six different teams.