He was apparently a FB/LB. And apparently a three-way threat, as he started out as a QB. This is from his Wikipedia page. I am LMAO at this description of him! These guys were beasts! Reminds me of the NHL of yore. No helmets on the players, no face masks on the goalies, massive post-retirement dental bills.
While at Illinois, Nitschke smoked, drank heavily, and fought at the drop of a hat. Never a good student in high school, his grades suffered at college. In his sophomore year in 1955, due to a depletion of players in the offensive backfield, Illini head coach Ray Eliot moved Nitschke from quarterback to fullback,[9] shattering his childhood dream of quarterbacking a team to a victory in the Rose Bowl. At this time, college football had reverted to primarily single-platoon football, meaning those players that were on offense had to switch to defense, and vice versa, when ball possession changed. On defense, Nitschke played linebacker. He proved to be a very skilled player and tackler as a linebacker, so much so that, by his senior year, Paul Brown considered him the best linebacker in college football.[10]
In his junior year in 1956 against Ohio State, Nitschke lost his four front teeth on the opening kick-off. Nitschke never wore a face mask and one of the Buckeye's player's helmets hit him in the mouth knocking out two teeth initially; the other two were hanging by the roots. He played the rest of the game.[11]