NFL football commissioner Roger Goodell delivers a Dean’s Distinguished Lecture at Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012, where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

NFL football commissioner Roger Goodell heads to the podium to deliver a Dean’s Distinguished Lecture at Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012, where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

NFL football commissioner Roger Goodell is surrounded by reporters after delivering a Dean's Distinguished Lecture at Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012, where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

NFL football commissioner Roger Goodell heads to the podium to deliver a Dean’s Distinguished Lecture at Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012, where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

Dr. Julio Frenk, Dean of the Faculty at the Harvard School of Public Health, speaks as NFL football commissioner Roger Goodell listens, at left, in Boston, Thursday, Nov. 15, 2012. Goodell delivered the Dean’s Distinguished Lecture where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

NFL football commissioner Roger Goodell, left, stands with Dr. Julio Frenk, dean of the faculty, at the Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012. Goodell delivered the Dean’s Distinguished Lecture where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

NFL football commissioner Roger Goodell delivers a Dean’s Distinguished Lecture at Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012, where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)

NFL football commissioner Roger Goodell delivers a Dean’s Distinguished Lecture at Harvard School of Public Health in Boston, Thursday, Nov. 15, 2012, where he discussed some of the rules that have been created to limit concussions in the game of football. Goodell said the league will do what it needs to do to protect the safety of its 1,800 players. (AP Photo/Elise Amendola)