Was the Will Smith-starring 'Concussion' softened to appease the NFL?

Will Smith stars as Dr. Bennet Omalu in "Concussion." (Columbia Pictures)From "Rocky" to "Hoosiers," the marriage of sports and film has generally been a happy one, filled with rousing moments of triumph that leave audiences cheering. But one upcoming film that takes a harder look at one of America's most popular pastimes — and one of the most powerful entities in the sports world — is stirring controversy months before its release.

Sony Pictures' "Concussion" tackles the thorny issue of head injuries in the National Football League. A report in the New York Times, citing emails that leaked after last year's devastating cyberattack on the studio, raises questions about whether the movie was…