When Sony Pictures Entertainment decided to make a movie focusing on the death and dementia professional football players have endured from repeated hits to the head — and the N.F.L.’s efforts toward a cover-up — it signed Will Smith to star as one of the first scientists to disclose the problem. It named the film bluntly, “Concussion.”

In the end even Sony, which unlike most other major studios in Hollywood has no significant business ties to the N.F.L., found itself softening some points it might have made against the multibillion-dollar sports enterprise that controls the nation’s most-watched game.

In dozens of studio emails unearthed by hackers, Sony executives; the director, Peter Landesman; and representatives of Mr. Smith discussed how to avoid antagonizing the N.F.L. by altering the script and marketing the film more as a whistle-blower story, rather than a condemnation of football or the league.

“Will is not anti football (nor is the movie) and isn’t planning to be a spokesman for what football should be or shouldn’t be but rather is an actor taking on an exciting challenge,” Dwight Caines, the president of domestic marketing at Sony Pictures, wrote in an email on Aug. 6, 2014, to three top studio executives about how to position the movie. “We’ll develop messaging with the help of N.F.L. consultant to ensure that we are telling a dramatic story and not kicking the hornet’s nest.”