A star NFL player was seen reading a self-help book during a playoff game. It’s now the top-selling book on Amazon

Philadelphia Eagles receiver A.J. Brown, seen here during a Jan. 5 game, says he brings the book to every game. "It gives me a sense of peace," he said.

Over the years, cameras have caught NFL players doing some memorable non-football things on the sidelines during games. Tom Brady once hurled an electronic tablet in frustration. Three members of the Seattle Seahawks were fined for eating hot dogs during a 1995 preseason game.

On Sunday evening in Philadelphia, as the Eagles hosted a playoff game against the Green Bay Packers, wide receiver A.J. Brown did something arguably even more intriguing.

He sat down and opened a book.

As the Eagles ground out their 22-10 victory, cameras showed Brown on a sideline bench, studying a well-worn paperback. One of the Fox Sports broadcast announcers chuckled. “I haven’t seen too many people read books (during a game),” he said.

The book is called “Inner Excellence: Train Your Mind for Extraordinary Performance and the Best Possible Life.” It was written by Jim Murphy, a former professional baseball player and self-described “performance coach” who helps athletes build mental toughness.

Brown is one of the Eagles’ best players. Only three passes went in his direction on Sunday, and he caught only one, for just 10 yards. Still, when he took questions after the game, he was cheerful.

This may have been the first time he’d been reading on camera. But he said it wasn’t the first time he’d read that book during a game.

“That’s a book that I bring every single game,” Brown said, adding that “my teammates call it ‘The Recipe.’”

Some passages were underlined and highlighted. Naturally, viewers were curious. The Eagles have a lot of fans, and the book quickly soared up the charts. On Monday afternoon, it was #1 on Amazon’s bestsellers list.

“As an outfielder in the Chicago Cubs organization, my sense of worth and identity revolved around my performance, mostly my batting average,” Murphy writes in the book’s introduction. “When I hit well, I walked tall and felt great. When I hit poorly, my shoulders slumped and my outlook was dark. Life was a roller coaster of emotions. I was a slave to results and it stifled my performance. I was afraid of failure and that fear kept putting my mind in the past and future.

“When I started coaching professional and Olympic athletes, I saw this over and over again: athletes had lost their joy and passion for life as they struggled under the pressure to perform. The fear of failure engulfed their lives.”

The book has helped propel athletes to higher levels of performance even when they were filled with doubt, Murphy writes. “But far more than that,” he adds, “you’ll learn how to live with deep contentment, joy and confidence in your everyday life.”

Brown told reporters the book helps him refocus after every drive, “regardless of if I score a touchdown or I drop a pass.” He will get more chances next Sunday, when the Eagles host another playoff game.

A reporter for Sports Illustrated reached Murphy by phone on Sunday night, as his book was suddenly going viral. Murphy said of Brown, “It’s really an honor to be a part of his life and to have a meaningful place in anyone’s life.”

By Monday afternoon, the book had at least one new five-star Amazon review, from a user named Todd. The headline of the review said “Go Birds.” The full text of the review said, “AJ Brown recommended this book, so I’m looking forward to reading this. Fly Eagles Fly.”

At least 1,044 people found Todd’s review helpful.