Complex sentence: Gibson did not want to expose his quarterback to further risk of injury (he had already taken some hits earlier in the season), nor did he want to risk his players being fined for violating the league's rules against fighting.
Split into simpler sentences: Gibson did not want to expose his quarterback to further risk of injury (he had already taken some hits earlier in the season). Nor did he want to risk his players being fined for violating the league's rules against fighting.