Will Lyman
Himself - Narrator
Harry Carson
Himself
Steve Fainaru
Himself
Mikey Collins
Himself - University of Pittsburgh Medical Center
Bennett Omalu
Himself - Medical Examiner
Ann McKee
Herself - Neuropathologist, BU CTE Center
Stan Savran
Himself - Pittsburgh Sports Reporter
Julian Bailes
Himself - Team Physician, Steelers, 1988-97
Jim Otto
Himself
Mike Webster
Himself (archive footage)
Steve Young
Self
Troy Aikman
Self (archive footage)
Leigh Steinberg
Self
Christopher Nowinski
Self