- Will Smith Dr. Bennet Omalu
- Alec Baldwin Dr. Julian Bailes
- Gugu Mbatha-Raw Prema Mutiso
- Arliss Howard Dr. Joseph Maroon
- Paul Reiser Dr. Elliot Pellman
- Luke Wilson Roger Goodell
- Adewale Akinnuoye-Agbaje Dave Duerson
- David Morse Mike Webster
- Albert Brooks Dr. Cyril Wecht
- Stephen Moyer Dr. Ron Hamilton
- Eddie Marsan Dr. Steven DeKosky
- Hill Harper Christopher Jones
- Richard T. Jones Andre Waters
- Mike O'Malley Daniel Sullivan
- Samara Lee Hija de Strzelczyk