Gable Steveson thought he achieved the impossible with his stunning last-second takedown of three-time world wrestling champion Geno Petriashvili to win gold at the Tokyo Games. Three years later, the 24-year-old Steveson is raising the degree of difficulty in approaching his next challenge: Pro football. Having never played a down of football in his life, he is the rawest of NFL rookies in opening his second week of practice with the Buffalo Bills on Tuesday.