told The New Republic that he would have to "think long and hard" before letting his son play football.

"Absolutely," the NFL commissioner insisted. "I have twin daughters just like the president, and I'm concerned when they play any sport. The second-highest incidents of concussions is actually girls soccer. So what you have to do is to make sure the game is as safe as possible. In the NFL, we're changing the rules, we're making sure the equipment is the best possible equipment, we're investing in research to make sure we can address concussions, not just to make football safer at the NFL level, but all levels in other sports."

"Do you now acknowledge that there is a link between the game and these concussions?" Schieffer pressed, noting that widows of NFL players had urged him to ask the question.

"That's why we're investing in the research," Goodell replied without fully answering the question. "So that we can answer the question, what is the link? What causes some of the injuries that our players are still dealing with? And we take those issues very seriously."

"For years the league would not acknowledge, really, that there was a connection," Schieffer pointed out. "You now acknowledge that there is a connection?"

"Well, Bob, again, we're going to let the medical individuals make those points," Goodell dodged. "We're going to give them the money, advance that science. In the meantime, we have to do everything we can to advance the game and make sure it's safe."

In fact, studies have shown that contact sports like football are linked to concussions, and NFL players are at a higher risk for Alzheimer's, ALS, abnormal brain proteins and depression.

Last year, more than 2,000 former professional football players filed a lawsuit accusing the NFL concealing information about the link between concussions and long-term brain injuries. And the family of former linebacker Junior Seau is also suing the league, alleging that his suicide was linked to concussions sustained while playing the game.

But for his part, Goodell insisted on Sunday that his organization had no role in concealing the risks of concussions.

"In fact, we're all learning more about brain injuries, and the NFL has led the way," he declared. "We started a concussion committee back in the mid-90s with the players' association to study these issues and advance science. We're obviously now learning more and more, and we're investing more and more. And I think that's going to lead to answers, even outside of brain injury, even to brain disease."