NFL Media Insider Ian Rapoport reported Sunday night, per two sources with direct knowledge of the linebacker's thinking, that Brooks took himself out of the game after learning that he would split time at his position more than anticipated, with Aldon Smith and Aaron Lynch playing in nickel packages instead of him. Mike Garafolo of FoxSports.com first reported the story.
Brooks did not even stand on the sideline with his helmet after getting benched. He sat on the bench without his helmet on, his cleats off, and his ankle tape cut off. After the game, Brooks confirmed that he's healthy. Brooks started over Smith on Sunday, but wound up sitting behind him for most of the game.
Lynch also played ahead of Brooks and responded with one sack, two quarterback hits, and two tackles for loss.
"Honestly, I don't know what happened there," Lynch said when asked about Brooks. "I don't know what the deal was. I love the guy. He's a big brother to me. As far as what happened off the field or on the field, I don't know what happened."
This isn't the first time the 49ers have made Brooks appear expendable. They dangled him in trade talks prior to the deadline, per Rapoport, which indicates he might be winding down his tenure with San Francisco. Harbaugh indicated Brooks' roster spot is not in jeopardy.
"We need Ahmad Brooks to win a championship," Harbaugh said. "I feel that wholeheartedly and have felt that way."