Donahue was selected in the 11th round of the 1978 NFL Draft by the Cincinnati Bengals. He played offensive guard for the Bengals in 1978 and 1979. Donahue later recalled: "It was fun playing a couple of years with the Bengals. It was a great experience lining up against legends like Randy White of the Dallas Cowboys and Joe Greene and the Pittsburgh Steelers. The first time you're in a stance against them, you're almost too excited to hit them. You get over that real quick when you realize there is no hesitancy at all on their part on hitting you hard."
^"Michigan Football Statistic Archive Query Page". University of Michigan. (The two games are: October 18, 1975 vs. Northwestern - Huckleby , Lytle , Bell ; September 18, 1976 vs. Stanford - Huckleby , Davis , Lytle )