What comes now for the NFL after a tumultuous season?

The NFL is still coming to grips with the dangers of professional football — a brutal sport that makes the league tremendously wealthy.

The Super Bowl closes a tumultuous year for the NFL.

Suicides by former NFL players. Thousands of others filing concussion lawsuits. New studies linking football to brain disease. Still no testing for human growth hormone. The specter of other purported performance-enhancing products — deer-antler spray, anyone? — being peddled to players.

A pay-for-pain bounty scandal. A lockout of officials resolved only after a ludicrous game-ending call. Zero minority hires for 15 coach or general manager openings.

And yet the league is as popular as ever.

Advertisers paid nearly $4 million per 30-second television commercial for the right to reach the 100 million or so Americans expected to tune in to Sunday's Super Bowl between the AFC champion Baltimore Ravens and NFC champion San Francisco 49ers. Eleven of the 12 most-watched TV programs during the last 2½ years were NFL postseason games, according to the league.

Uncertain, though, is what the future holds for an NFL still coming to grips with the dangers of a brutal sport that makes it tremendously wealthy.

RECOMMENDED: Super Bowl XLVII: 18 pregame facts on Ravens and 49ers

"The game has changed and keeps changing. ... It is such a violent game, and such a collision game, that careers are going to be kind of like not long at all. Because you take those licks — you've only got so many in your body, and at some point that's going to wear it out," said Ravens running backs coach Wilbert Montgomery, who played that position for the Philadelphia Eagles and Detroit Lions from 1977-85.

Montgomery said he got six concussions in one season alone, and others along the way, including one that knocked him out cold a few days before playing for the Eagles in the NFC title game at the end of the 1980 season.

"I know one thing: Back then, it didn't make any difference. They gave you smelling salts and then, after that, you went back in," Montgomery said. "I have headaches all the time. That's why I say my wife is always messing with me when I have outbursts, saying, 'You've been hit too many times upside the head.'"

Montgomery laughed for a moment. Then he rubbed his forehead and continued talking, mentioning former teammate and friend Andre Waters and opponent Dave Duerson. Both committed suicide; researchers studied their brain tissue and found signs of chronic traumatic encephalopathy, or CTE, a degenerative disease also found in boxers and often linked with repeated blows to the head. Former star linebacker Junior Seau, who shot himself in May, also was found to have CTE. Baltimore's starting center on Sunday, Matt Birk, has pledged to donate his brain for study when he dies.

"It's a serious thing," Montgomery said. "It's scary."

When the President of the United States refers to fans perhaps having a guilty conscience when watching a game and parents thinking twice before allowing a child to play — as Barack Obama did in a recent interview with The New Republic — it sends a strong signal about what confronts the NFL today.

"If I was worried about my health," 49ers quarterback Colin Kaepernick said, "I wouldn't be playing football."

So the league must figure out how to deal with "walking a fine line," as 49ers CEO Jed York described it: The two-sided task of making the game safer, which Commissioner Roger Goodell acknowledges is imperative, while not making it "too safe," thereby diminishing the popularity of an enterprise that is violent by its very nature.

"There's no question that that is a bit of a conundrum. But to me, we've got to place more weight on player safety," New York Giants co-owner John Mara said. "The rules changes that we've implemented over the past five or six years have not made the game any less exciting. If anything, the game is as exciting as ever, and I strongly believe that we can make additional improvements in the rules and we're not going to lose anything in terms of excitement on the field."

Ravens owner Steve Bisciotti is convinced the NFL will strike the proper balance.

"What did they do for boxing when they made them go from 6-ounce, to 8-ounce to 12-ounce gloves or whatever? Did it change boxing? Not really," Bisciotti said. "I believe that with every change, there will be a correction. ... And I believe that we as a league and the [players' union] will agree on things that don't take football out of football."

In a series of moves that began shortly after Goodell was grilled at a congressional hearing, the league has changed concussion return-to-play guidelines, adjusted rules for kickoffs — and floated the idea of eliminating them altogether — stepped up punishment of illegal hits, and stopped arguing against the players' wish for independent neurology specialists on the sidelines during games.

Even if there are some players who in one breath worry about whether their health is imperiled, and in the next say, "We're basically going to be playing two-hand touch in a while" — Baltimore nose tackle Terrence Cody's words this week — the head of their union points out that prudence and popularity do not have to be mutually exclusive.

"The reality of it is, 'football as we know it' has evolved over decades. ... Our job is to have an unqualified commitment to the health and safety of the people who play the game, and then to make those changes where we see necessary," NFL Players Association executive director DeMaurice Smith said.

"I don't think there is this thing of 'football as we know it.' What we have is football that has constantly developed," Smith said. "And even with all of the [recent] rule changes ... my guess is this Super Bowl will be the highest-rated of all time."

Indeed, while the concussion lawsuits mount — a U.S. District Court judge in Philadelphia will hear oral arguments in April on the NFL's effort to dismiss a group of cases — and questions arise about what insurers will charge the league moving forward, the money does keep rolling in. Revenues already topped $9 billion at the time of the last labor deal in 2011, and new TV contracts will only help increase it.

"At $10-to-$12 billion? It ain't going nowhere," said Warren Sapp, a retired defensive tackle elected Saturday to the Pro Football Hall of Fame and who now works for the NFL Network, another piece of the league's marketing machine. "We play a beautiful game. We hit each other. [Players] have to take care of each other better. Then it will be fine."

Meantime, the NFL continues to look for new ways to increase its cash flow.

During his state of the league address two days before the Super Bowl, Goodell did not rule out increasing the regular season from 16 to 18 games, and he reiterated the possibility of expanding the postseason, too. He announced that two 2013 games in London already are sold out, and there could be three in future seasons — down a path that, eventually, could lead to a franchise based in Britain.

"For you to be adding games to the season, are you looking out for player safety? Or are you trying to generate more player revenue?" 49ers receiver Randy Moss said. "If you're trying to look and protect the players, and keep it healthier and better every year, I don't think it's a good idea."

Several players in this year's Super Bowl were incredulous that the league would even consider more games. A handful voiced concern over a disconnect between players and owners.

The president of the NFLPA, former Ravens cornerback Domonique Foxworth, said he wonders how truthful Goodell and other NFL officials are being when they say — as they often do — that players' well-being is a priority.

"The league, their No. 1 focus — at least they say their No. 1 focus — is health and safety. And we say our No. 1 focus is health and safety. How come we have such a hard time moving the ball on some health and safety issues?" Foxworth said. "I believe health and safety is on their list of top five things, but it comes in well behind increasing the bottom line."

RECOMMENDED: Super Bowl XLVII: 18 pregame facts on Ravens and 49ers