Director of 'Concussion' discusses Will Smith's unrecognizable transformation

Peter Landesman, director of "Concussion," stopped by Good Day LA on Monday to talk about the new film.

Based on a true story, "Concussion" follows American immigrant neuropathologist Dr. Bennet Omalu (played by Will Smith) who makes the first discovery of CTE, a football-related brain trauma, in a professional player.

Omalu then goes on a quest to expose the truth despite the NFL's efforts to conceal it.

Landesman talked about what inspired him to make the film and the transformation Will Smith went through to prepare for the role.

Watch the full interview above.

"Concussion" hits theaters on Christmas day.

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