in a november 1940 game against illinois, sukup suffered a blow to the head while blocking for harmon. he was knocked unconscious, suffered from temporary amnesia and was later hospitalized for several days after suffering recurring headaches. sukup was propped up in a bed at university hospital when the wolverines left to play minnesota and listened by radio from his hospital bed as the team suffered its only loss of the season. he missed the last three games of the season due to the concussion and did not compete further as a football player. some have concluded that sukup was on track for selection as an all-american until the injury ended his season.