For as powerful -- and, frankly, troubling -- as the PBS Frontline documentary League of Denial was, one of the biggest issues facing the NFL when it comes to head injuries and player safety is that players have to self-report those injuries.
Sherman recounted the experience this week in an article he wrote for TheMMQB.com.
"On the game's seventh play (Seattle faced Cincinnati in Week 8 of the 2011 season), I trailed my receiver down the left sideline and looked back to see Andy Dalton toss it underneath to Chris Pressley, their 260-pound fullback," Sherman said. "As he turned up the sideline I came down hard, squared up, and dove at his legs. His right knee connected with my temple, flipping him over my head. I got up quickly and shook my head back and forth to let them know nobody is running me over.
"The problem was that I couldn't see. The concussion blurred my vision and I played the next two quarters half-blind, but there was no way I was coming off the field with so much at stake. It paid off: Just as my head was clearing, Andy Dalton lobbed one up to rookie A.J. Green and I came down with my first career interception. The Legion of Boom was born."
Sherman, like many players, knows the inherent dangers of playing a violent sport.
"[W]e understand this is a dangerous game with consequences not just in the short term, but for the rest of our lives," he said. "All of us NFL players, from wide receivers to defensive backs, chose this profession."
Even if Sherman suspected a teammate was concussed, he'd keep it to himself.
"Sometimes I can tell when a guy is concussed during a game -- he can't remember things or he keeps asking the same questions over and over -- but I'm not going to take his health into my hands and tell anybody, because playing with injuries is a risk that guys are willing to take," Sherman said. "The players before us took that risk too, but they still sued the league because they felt like they were lied to about the long-term risks. Today, we're fully educating guys on the risks and we're still playing. We have not hidden from the facts."
Sherman is thoughtful and honest, but his story is the latest example of not just the brutality of tackle football, but what the league is facing as it tries to make the game safer.
As for whether he'll speak up the next time he's concussed ... don't count on it.
"And the next time I get hit in the head and I can't see straight, if I can, I'll get back up and pretend like nothing happened," Sherman said. "Maybe I'll even get another pick in the process."
And therein lies the problem for the NFL.