During most games, NFL players can be found on the sideline going over video, talking to coaches and teammates, or just catching their breath from a previous play. But when Fox Sports panned to Philadelphia Eagles wide receiver A.J. Brown during Sunday's playoff game, he was reading. The video went viral.

FoxSports

While viewers and reporters were shocked, Brown said it is something he does every game, returning to specific passages in a book called Inner Excellence by Jim Murphy. (Thanks to Brown, the title is now the No. 1-selling book overall on Amazon.)

Reporters questioned him about it after the game, asking whether reading the book was a sign that he was frustrated with the game.

"I figured that's what y'all probably thought," he said. "Why do you always think I be frustrated? Dang, I like to read."

Brown was celebrated on social media by Jean Darnell, the new director of library science for the School District of Philadelphia.