"I probably won't be getting my free Super Bowl tickets this year," said actor Will Smith, who plays Dr. Bennet Omalu, the man who discovers the link between American football and chronic traumatic encephalopathy (CTE).
As a noted Philadelphia Eagles fan and parent of a former high school football star -- Smith once traveled between China and Los Angeles for 10 straight weeks to watch son Trey compete -- the actor admitted feeling conflicted about the film.
But meeting Nigeria-born Omalu convinced him that the story needed to be told.
"Dr. Omalu is an immigrant, and a big part of why he fought so hard to have this information come out is because he believes in America and American ideals," Smith told CNN's Rachel Nichols ahead of the movie's U.S. release next week.
"I believe firmly in the ideas and in the concepts of what this country stands for, and I'm impelled and compelled to do whatever I have to do to make sure they aren't trampled upon."
While shooting in Pittsburgh, Smith also met with family members of former NFL players who succumbed to CTE -- including those of former Steeler "Iron Mike" Webster.
The Hall of Fame center was an anchor on four Super Bowl winning teams before succumbing to substance abuse and homelessness. In 2002 he died at age 50, with pathologist Omalu assigned to his autopsy.
"The production was extremely heavy," Smith recalled. "You know, it's not just a movie. It's people's lives that we're trying to do justice to their suffering."
In the months leading up to the release of "Concussion," leaked Sony emails appeared to express concern among its filmmakers not to upset the NFL, though director Peter Landesman insisted to the New York Times that the plot line was not altered.
"We welcome any conversation about player health and safety," said the NFL in a statement sent to CNN. "Broader and deeper awareness of these issues will positively impact all athletes.
"The NFL has made numerous changes to the game to enhance the health and safety of players at all levels of football. These include nearly 40 rule changes in the last decade, strict concussion protocols, and better training and sideline medical care.
"We're seeing measurable results, including a 34% decrease in concussions in NFL games since the 2012 season.
"Additionally, we are funding independent scientific and medical research and the development of better protective equipment to advance further progress. The game continues to change, and the safety of our players remains our highest priority."
One of the players, former Chicago Bears free safety Dave Duerson, who was known for his aggressive tackles, committed suicide in 2011 and left instructions that his brain be sent to Boston University's CTE Center
Researchers reported that Duerson was correct in his suspicion, though his brash portrayal in the film by Adewale Akinnuoye-Agbaje is disputed by his family.
Fellow Hall of Famer Junior Seau, who committed suicide in 2012, also suffered from CTE.
Currently, NFL players are tested for symptoms of concussion by team medical staff alongside independent neurotrauma consultants before they are allowed to return to play. Any player who loses consciousness is barred from returning on that day, a league spokesman confirmed.
The NFL has had a number of run-ins with Hollywood over the years.
The 2003 ESPN drama "Playmakers"
lasted just one season before former league commissioner Paul Tagliabue rang ex-Disney head Michael Eisner to complain of the subject matter depicted in the fictional league (drugs, domestic violence, paralysis, homosexuality, to name a few), according to the New York Times.
Tagliabue deemed the show ''one-dimensional and traded in racial stereotypes, and I didn't think that was either appropriate for ESPN or right for our players."
Disney is the parent company of ESPN, which has several broadcasting contracts with the NFL. Eisner decided against greenlighting the series for a second season.
"How would (Disney) like it if Minnie Mouse were portrayed as Pablo Escobar and the Magic Kingdom as a drug cartel?" Eagles owner Jeffrey Lurie told the Philadelphia Inquirer, referring to the infamous Colombian drug lord.
To a lesser degree, the 1999 Oliver Stone film "Any Given Sunday" cast a negative light on the league -- mainly through a corrupt team doctor played by James Woods.
Though a few former and then-current NFL players appeared in the film (Lawrence Taylor, Terrell Owens), the league did not sanction the use of its logos.
The prevalence of head injuries is not just a hot topic in the NFL.
During the first half of soccer's 2014 World Cup Final, Germany midfielder Christoph Kramer appeared to lose consciousness after his head collided with an Argentina player.
Clearly dazed, Kramer was treated on the pitch before reentering the match only two minutes later, ostensibly without any check for concussed symptoms.
Beginning last season, England's Premier League stipulated that players who suffer head injuries must come off the field and be examined by team doctors. In the past, medically unlicensed members of staff were deemed sufficient.