Willis was small for a lineman at 202 pounds, and despite signing up to play for Brown he was initially expected to focus on track and the 60-yard and 100-yard dashes. Brown, however, brought him onto the football team as a sophomore in 1942. Willis played middle guard, a defensive position opposite the center. That year, the Buckeyes posted a 9–1 record and won the Big Ten Conference. The team was voted national champion by the Associated Press, a first for the school.