Let's travel back in time to November 2009.
The Pittsburgh Steelers were scrapping for their playoff lives after an overtime loss to the Kansas City Chiefs in which Ben Roethlisberger was kicked in the head during a sack and sustained a concussion.
With the rival Baltimore Ravens next on the docket, a question of if Roethlisberger would play was in question.
(Spoiler alert: He missed the game. Hines Wards caused a kerfuffle. The Ravens won in overtime. The Steelers fell to 6-5, would end the season 9-7, lose a tiebreaker to the Ravens and miss the playoffs.)
On Saturday at a concussion conference at the University of Pittsburgh Medical Center, Steelers athletic trainer John Norwig outlined in candid detail how and why Roethlisberger didn't play.
Norwig said Big Ben passed concussion tests early that week and practiced Wednesday, Thursday and Friday.
"By Thursday and Friday, he was perking up big-time," Norwig said Saturday, per USA Today.
But after that Friday practice, Roethlisberger didn't feel so hot.
"He said, 'John, I just don't feel right,'" Norwig said. " ... So I had to go to the head coach (Mike Tomlin) and say, 'Hey, look, he's symptomatic. He can't play.'"
Saturday morning before the flight to Baltimore, Roethlisberger reiterated that he just didn't feel right. At the team dinner that night, however, he told Norwig he felt well again.
"Our quarterback comes up and says, 'I'm feeling great. ... I have no headaches. ... I just ran up and down the hall a couple of times. I feel good,'" Norwig said.
It didn't matter. The Steelers stuck by their rule that if a concussed player remains symptomatic within 24 hours of the game, he will not play. It was a decision Norwig said was the correct call.
"It was the right thing to do," Norwig said. "We lost the game, and maybe we would have won. Who knows? It doesn't matter."
At the time, the decision to sit Roethlisberger led Ward to question the quarterback's toughness.
"I could see some players or teammates questioning, like 'It's just a concussion. I've played with a concussion before,'" Ward said in an interview with NBC's Bob Costas before the Sunday night game. "It's almost like a 50-50 toss up in the locker room. Should he play? Shouldn't he play? It's really hard to say."
Ward later apologized on Facebook for the comment.
Roethlisberger himself said the week after the loss to the Ravens that he wanted to play -- but he understood the team's decision.
"(I) respected what they said," Roethlisberger said in 2009. "You do have to think about your future and your family. It's not fun, but you can get knee replacement surgery, you can have rotator cuff surgeries, but you can't get a new brain."
Norwig's blow-by-blow of what happened that last week in November 2009 illustrates how far we've come in four years in terms of understanding concussions, the protocol and respecting the lasting effects on the brain.
Follow Kevin Patra on Twitter @kpatra.