The NFL and several manufacturers have focused resources on improving helmet safety. But helmets, Bailes said, may now be part of the problem.
"The helmet has given a false sense of security, and I think for many players it has been a weapon. It has led paradoxically, unfortunately, ironically, to some of the injuries that we are currently seeing," he told "Nightline." I think the helmet as it has evolved in parallel, has led paradoxically to players sticking their head in with a false sense of security."
And while helmets cannot protect the brain within the skull, there is a further problem: What about players like Webster who never experience a career-ending concussion but instead suffer the cumulative effects of up to 50 head collisions per game, season after season?
"I think there is a phenomenon called subconcussive impacts, a subconcussive blow? the question it begs is: does that lead to microscopic damage? Can it lead to that?" Bailes said. "We don't have that definitive answer. But we've got several linemen who did not have career-ending concussions, who were later found at an earlier age to have extensive brain damage."
"Nightline" spoke to Dr. Joseph Maroon, a neurosurgeon and current doctor for the Pittsburgh Steelers, who represents the NFL. He's also a member of the NFL Mild Traumatic Brain Injury Committee.
When asked if he was concerned about that area where an individual isn't concussed but nevertheless has taken repeated blows to the head, Maroon said it's an area that should be more carefully examined.
"I think that's an important observation and consideration. Absolutely, I think that's an important new emphasis on what happens to the brain and head in football," Maroon said.
The NFL says it has implemented several safety regulations to protect players in the event of an overt concussion.
"It clearly has instituted educational programs to inform the athletes, the players, the coaches, and the trainers, of just what is a concussion and of the long term consequences of concussion," said Maroon. "It's instituted a whistle-blower hotline so that if any athlete feels like he is being pushed back into play too soon, he can directly report this anonymously to the NFL."
In a statement provided to "Nightline," the NFL said: "We have more resources than ever devoted to the care of this injury and to the education of players and their families, as well as coaches and team personnel. ... Hundreds of thousands of people have played football and other sports without experiencing any problem of this type. There continues to be considerable debate within the medical community on the precise long-term effects of concussions and how they relate to other risk factors, including pre-existing conditions or family history."
But the issue of subconcussive blows to the head is far more problematic to address because no method of measuring them currently exists.
"I think there is yet more to learn. And I think the phenomenon of subconcussive impacts is important to understand," Bailes said.
A phone survey commissioned by the NFL and completed at the University of Michigan found that pro football players are 19 times more likely to be diagnosed with dementia, Alzheimer's disease or other memory-related illness than the same 30- to 49-year-old-age group in the general population.