There are times when the NFL can seem like the Teflon Don of professional sports leagues.
When the steroid issue in Major League Baseball turned into a moral crisis and investigation from Congress, the NFL just chugged along - a positive test here and there - but never found any need to examine its soul along the way.
As the most popular betting vehicle in North America, the NFL can proudly take a harsh anti-gambling stance, and do so with a straight face telling those nasty folks to from the Las Vegas Convention and Tourist Bureau to take their advertising money elsewhere.
And all those stories of retired NFL players having a tough time with life after football? Well they haven't dampened the fans' enthusiasm for the game one bit, with new viewership records being established one year after the next.
So no, the NFL and commissioner Roger Goodell aren't used to being on the defensive. But that's exactly where the league has found itself during an off-season unlike any other - one that has shone a bright light on the true nature and effects of what goes on between the white lines for our entertainment.
First came the lawsuits from former players, spreading like wildfire in recent months until now roughly 1,500 former players - including some of the biggest names of the game - are suing the league for negligence over its management of head injuries.
Then came the bounty scandal, which not only made the NFL in general appear barbaric but managed to suck all the feel-good out of the New Orleans Saints' Super Bowl run of two seasons ago.
And finally - just last week - came the suicide of Junior Seau, an NFL icon and future Hall of Famer. He died at age 43, just over two years removed from the playing field. It's too early to conclude that football contributed to Seau's death, but given the context, it hardly seems inappropriate to speculate.
It's stunning how quickly the issues around head injuries in professional football have come to the front burner. Goodell took over the NFL just less than six years ago at a time this wasn't even a blip in the public eye, with collective bargaining and off-field discipline the most important issues he was facing.
Remember one of the very first ideas Goodell brought forward as the new face of the NFL? An 18-game regular season, a notion that seemed reasonable at the time but which, in light of recent events, seems as ridiculous as it is unlikely to occur.
How fast things change.
It now seems clear that Goodell's ability to steer his league around the issues surrounding concussions and head injuries will define his time as commissioner. And though his current contract extends to 2018, there is every reason to believe the NFL will be dealing with this issue until then and beyond, given how difficult it is to define where it begins and where it ends.
And the question no one seems able to answer right now is whether it's actually possible to make professional football safe?
Or, as New York Times columnist William Rhoden recently suggested on an episode of ESPN's Sports Reporters - is professional football akin the tobacco industry of yesteryear, defiantly insistent that it's product can be made safe when in fact it cannot?
And is it time for the NFL to face that fact?
Will players of the future have to acknowledge the risks of the game up-front, forfeiting their right to sue based on understanding the risks they are taking? But how does that sort of thing play out at the college, high school or grass roots levels?
Is it possible that the very nature of football as it is now played could change, so that it becomes a game far less about hitting and more about wrapping-up and tackling? But what about all of those repeated low-impact hits which may be just as damaging as the big ones over time? And what about full-contact practice?
The NFL is in the midst of a cultural shift, one that began in the fall of 2010 when the commissioner vowed to take a harder stand on helmet-to-helmet hits, was emphasized by restrictions on practice negotiated with the players as part of last summer's collective agreement and was then accelerated by the manner in which he came down on the Saints players and coaches in the bounty scandal.
It would be nice to believe this was simply the case of a league doing the right thing, but it's impossible to ignore the upcoming need for the NFL to present itself in court as a league doing all it can to minimize the hazards of the workplace for its employees.
Were it not for this issue and the threat of liability through the courts, Roger Goodell might have the easiest job in all of sports, captain of an economic juggernaut that that shows no signs of slowing down.
But looking at the landscape ahead, there's every reason to believe he's going to earn every penny he makes.