With regard to the issue of concussions and its' potential consequences, the NFL has apparently adopted a 'wait and see' approach and current active players seemingly prefer to 'play now and pay later'.

Information continues to emerge that links multiple concussions, brain injury, depression and early onset dementia. Add to this sequence of events CTE (chronic traumatic encephalopathy).

(http://www.nytimes.com/2009/01/28/sports/football/28brain.html?emc=eta1)

By the NFL's own admission, the documented concussion rate in the NFL is approximately 1 concussion every 2 games.  Some concussions are not reported therefore the actual rate is undoubtedly higher.

Unfortunately, those best positioned to apply leverage to the NFL, active players, do what young men commonly do... Seriously consider the potential consequences of their actions only after the fact. 

Why should I have money withheld from my current salary to care for my retired brethren or myself, when my playing days are over?  Active players don't want to pay for the benefits that they may desperately need once they retire.

Active players are fond of saying that football is a violent game.  Unfortunately, they will realize how violent it truly is once they retire.