Pro football players are not getting any smaller. When they hit each other on the field pain seems inevitable. In most cases pain motivates people to do something different in the future. The rewards of pro sports (money, fame, women) overpower even pain. Or they motivate someone to take painkillers.
Owners and coaches might ignore a pain pill problem for the sake of keeping a strong player on the field. Strong players, great teams, winning seasons, getting into the playoffs, winning the Super Bowl: Coaches and owners have many potential rewards as well.
It is hard to see how these problems–overuse of pain pills in the NFL, and active efforts to cover up that use–are going to be resolved. Even under less dramatic circumstances people in chronic pain easily overuse pain pills. Serious change might come from changing football rules to reduce injuries, establishing weight limits (as is done in boxing), ongoing drug testing of players, or having regular mandatory physicals by impartial physicians and mandatory time off for specific injuries. None of these changes seems likely. The best players and former players can hope for now is the possibility of more money from the NFL, perhaps via litigation. Given the salaries many players already earn it is uncertain how sympathetic juries will be.
The safest way to avoid pain from football injuries is to stop playing football. Players have been free to choose that course of action since the NFL (and college and high school football) have been around. And the rest of us are free to stop watching and supporting football. As I said, it is hard to see how these problems are going to be resolved.