Nessler began his professional broadcasting career sharing play-by-play radio duties with Al Ciraldo on Georgia Tech basketball on WGST-AM from 1980-81 through 1984-85, and handled the play-by-play for the Atlanta Falcons from 1982 to 1988 on WGST and WSB-AM before assuming the same position for the Minnesota Vikings during the 1988 and 1989 seasons. He also called preseason telecasts for the Miami Dolphins for several years, and has done play-by-play of ACC football and basketball telecasts for Jefferson-Pilot.