Asked by Bob Schieffer on Sunday whether the league hid the risks of head injuries, Goodell said, "No."
Goodell declined to confirm that there is a proven connection between the sport and medical problems in retired players. He emphasized that the NFL is funding research to learn more about the risks and changing rules to make the game safer.
Goodell said he had no concerns that football could go the way of boxing, a sport now far less popular than in its heyday.
"I couldn't be more optimistic about it because the game of football has always evolved," the commissioner said.
"Through the years, through the decades, we've made changes to our game, to make it safer, to make it more exciting, to make it a better game for the players, for the fans, and we have done that in a very calculated fashion."
RG3 plays keep-away
There's only one way Robert Griffin III wants to go to the Super Bowl.
As a player.
The electrifying Washington Redskins quarterback came to New Orleans to pick up the Associated Press 2012 offensive rookie of the year award. But he wasn't in attendance at Sunday's game between the Baltimore Ravens and the San Francisco 49ers. He watched it with his family instead.
"I'm a firm believer you don't go to the Super Bowl unless you're playing in it," Griffin said.
Baltimore Ravens coach John Harbaugh and San Francisco 49ers coach Jim Harbaugh are hardly the only high-profile siblings who've squared off in their arena of expertise. The Associated Press asked some others who can relate how to handle going against a family member in the Super Bowl.
When quarterbacks Eli and Peyton Manning squared off during a regular season game, at least one parent didn't have too hard a time deciding who to root for. "I knew my mom was going to root for me - I'm the baby of the family, so that was an easy one," Eli Manning said.
But sibling battles can be tough on parents, the New York Giants quarterback said.
"It's hard to be excited for one child winning a game and also disappointed for the other one that didn't," he said.
As for the Harbaugh brothers: "I think they're just both trying to figure out how to get a win."
Eli's brother Peyton Manning says the Harbaughs handled the week well, knowing one brother was happy Sunday night while the other was disappointed.
"Neither would be in this game if they weren't excellent coaches, and no matter . . . they're still excellent coaches," Peyton Manning said.