It was disclosed this week that two football greats, quarterbacks Ken Stabler and Earl Morrall, were the latest of dozens of players found to have had a degenerative brain disease linked to repeated head hits.
Yet N.F.L. Commissioner Roger Goodell, when peppered with questions about player safety on Friday, gave one of his most earnest endorsements of the safety of the game.
Most of his comments echoed previous statements: that the league is changing its rules to reduce risks, has adopted new equipment and technology, and is spending millions of dollars on research.