In his 20-year N.F.L. career, Junior Seau established himself as one of the game’s greatest linebackers. He committed suicide in 2012 at age 43 and was subsequently found to have had a degenerative brain condition linked to repeated hits to the head. Before his death, Seau told his daughter Sydney, 21, that she should speak on his behalf if he made it into the Pro Football Hall of Fame. But the Hall, citing a five-year-old policy of not letting others give full speeches for deceased inductees, did not allow Sydney to deliver her speech.