Football is a brutal sport, especially in the NFL. The players know the risks going in, so they bear a large part of the responsibility. If Seau’s brain show massive trauma, as a linebacker you have to think the majority of it was inflicted by himself.
No they don’t know the risk going in. The league lied to them and told them there was no long term risk. That’s part of why they’re being sued, and they’re going to lose those suits. And when you look at the Henry situation with ZERO reported head injuries in college or the pros you have to start to think some of this damage is happening in high school or even peewee, when they’re kids and WAY know know the risk.