The NFL says it did not ask ESPN to 'divorce themselves from the project.' (USATSI)

NFL Commissioner Roger Goodell has made it clear that player safety is the league's top priority. But according to a New York Times report, pressure from the NFL led to ESPN pulling out joint project with PBS' Frontline investigating head injuries.

Frontline and ESPN had been working for 15 months on the investigative documentary, which was to be televised in October. But ESPN's role came under pressure from the league after a trailer for the documentary was released in early August, sources told the Times.

More details:

Last week, several high-ranking officials convened a lunch meeting at Patroon, near the league’s Midtown Manhattan headquarters, according to the two people, who requested anonymity because they were prohibited by their superiors from discussing the matter publicly. It was a table for four: Roger Goodell, commissioner of the N.F.L.; Steve Bornstein, president of the NFL Network; ESPN’s president, John Skipper; and John Wildhack, ESPN’s executive vice president for production. At the combative meeting, the people said, league officials conveyed their displeasure with the direction of the documentary, which is expected to describe a narrative that has been captured in various news reports over the past decade: the league turning a blind eye to evidence that players were sustaining brain trauma on the field that could lead to profound, long-term cognitive disability.

“At no time did we formally or informally ask them to divorce themselves from the project,” Greg Aiello, a spokesman for the NFL, told the Times. “We know the movie was happening and the book was happening, and we respond to them as best we can. We deny that we pressured them.”

And ESPN spokesman Chris LaPlaca said Thursday that ESPN's decision wasn't based on concerns about its contractual relationship with the NFL. Instead, the network said in a statement that it was ending its association with Frontline because it did not have editorial control on what appeared on the series. ESPN, which is owned by Disney, pays the NFL more than $1 billion a year to air Monday Night Football.

But Raney Aronson-Rath, an executive producer for Frontline, told the Times that the ESPN executives understood for more than a year that Frontline would have editorial control over what it televised and put on its web sites, and ESPN would have control over everything it televised or put on its web sites.

The documentary is set to air on Oct. 8 and Frontline bills it as "a special two-part investigation examining whether -- as thousands of former players allege -- the NFL has covered up the risks of football on the brain."