In a letter distributed Thursday, NFL Commissioner Roger Goodell claimed “the game is safer and more exciting today than ever [and] we are committed to pursuing a path that ensures the rewards of playing football continue to far outweigh the risks.” (Nam Y. Huh/Associated Press)

The e-mails began landing in inboxes early Thursday morning, the latest message of progress and change from NFL Commissioner Roger Goodell. “The NFL season is off to another exciting and competitive start,” the more than 1,000-word letter began. “I want to thank you and all NFL fans for your passionate support.”

Goodell went on, his remarks evolving more into a reminder of the league’s focus on player safety, the reduction of head injuries and what can be done to make the NFL safer in the future. But was it an innocent and unprovoked state-of-the-league notice to supporters or merely a timely move to soften reaction to a pair of approaching threats to the NFL brand?

“League of Denial: The NFL, Concussions, and the Battle for Truth,” a book written by two ESPN investigative reporters, is expected to detail how the league not only ignored a scientific link between football and brain injuries decades ago but used its power to discredit supporting studies. The book will be released Tuesday, the same day PBS will air a corresponding and similarly titled “Frontline” documentary.

On Thursday, it was easy to make the connection that Goodell’s letter, sent to 10 million subscribers on the NFL’s mailing list, was a preemptive measure five days before the next wave of criticism.

“The issue of player health and player safety is something that has grown and is something the NFL doesn’t want to react to. It’s something they want to get out in front of,” said John Ourand, a media reporter for the Sports Business Journal. “This is an issue that they know they can’t put their hands over their eyes and hope it goes away. They have to deal with this, and I think this is all part of trying to do that.”

The Post Sports Live crew debates whether the defense's impressive performance in the Redskins' win over the Oakland Raiders is a reason to be optimistic for the rest of the season. (Post Sports Live/The Washington Post)

Greg Aiello, a spokesman in the league office, said Goodell’s open letter — the 11th note sent to supporters since 2011 — was “planned independently” of the forthcoming projects and compelled by no outside factor. “It is part of regular communication that the commissioner has with fans,” Aiello wrote in an e-mail.

Still, suspicions exist, particularly after ESPN announced in August it was ending a collaborative agreement with PBS to produce and market the “League of Denial” documentary. The sudden announcement prompted speculation that ESPN was pressured to distance itself from the project by the NFL, the sports giant’s most powerful broadcast partner. League officials have denied asking ESPN to back out of the project.

That was part of a late-summer two-step performed by the NFL, which also in late August agreed to a $765 million settlement after thousands of retired players sued the league for exposing them to concussion-related brain injuries.

In Thursday’s letter, Goodell emphasized the league’s commitment to change, ranging from eliminating the “head slap” in the 1970s to outlawing the “horse-collar” tackle in the 2000s. Goodell wrote that a recent emphasis on penalizing hits using the crown of the helmet is part of the league’s focus on evolving the game.

“We are proud that the game is safer and more exciting today than ever, but we are never satisfied,” the letter stated. “In keeping with our history, we are committed to pursuing a path that ensures the rewards of playing football continue to far outweigh the risks.”

David Carter, the director of the sports business institute at the University of Southern California, said Goodell’s letter might have targeted fans — but that it was clear he was speaking to a larger audience.

“The messaging is very important,” Carter said. “It’s not just to the fans. It’s to the people who are funding the NFL. Sponsors want to know that the league is doing what it can for player health and safety.”

Mark Kelso, a former Buffalo Bills safety who wore a specially padded helmet during his playing career and remains active in trying to improve helmet safety, said the NFL has made good on promises Goodell has made in the past.

“There has been a little bit of a culture shift,” Kelso said. “The NFL has done some really positive things. It’s supportive both financially and from a marketing standpoint of some positive changes. I think there have been appropriate rule changes. . . . I do think there have been some obstacles created for pushing technological advancements forward. I think the NFL can help to push these forward, and we are starting to see that.”

Kevin Guskiewicz, who has been on the NFL’s Head, Neck and Spine Committee since 2010, has spoken often with Goodell. Guskiewicz said Thursday’s note might do little to alter the opinion of critics or to change the minds of those convinced it was only an effort to shield the league from a barrage of approaching criticism. But he said the letter should remind NFL followers that, yes, necessary changes have been made.

“He’s just trying to remind people that we’re doing more than the average person realizes,” said Guskiewicz, who emphasized he isn’t paid by the league.

“I guess I’m not sure how anyone could argue that Roger Goodell hasn’t made health and safety a priority the last three or four years,” he said. “Even if it was a preemptive strike at the upcoming release of this book, so what? He’s been putting forth the initiatives he outlined in the letter for three years now, and that was long before the book was ever thought of.”