Then, just like that, he was gone. Unlike other players who often attempt to hide dangerous concussions for fear of losing their jobs, Smith acknowledged he was still suffering from blurred vision, and was replaced by Kaepernick for the next game, against the Chicago Bears. The 49ers won that game easily, and the new kid was so impressive that Smith immediately became old news. Smith was medically cleared to play the following week, but he spent that game on the sideline. He has played in only one game since, throwing one pass during one meaningless moment.
"It's not about fair, that's not what this is about," Smith said. "We play football. I'm the backup. That's what it is."
That Smith's admission of concussion symptoms cost him his job will send a chill throughout a league filled with players who already take great personal risks for the sake of a snap. But Smith says if he had to do it all over again, he would still protect himself and his family.
"We're all going to finish this game at some point, you have a lot of life ahead of you, and we only have one brain," he said. "It was an easy decision."
The results of that decision are rarely seen in a sport where successful starting quarterbacks for championship-caliber teams are changed in the middle of the season about as often as team logos. Only two quarterbacks have started a Super Bowl with less experience than Kaepernick's nine starts. The last time this game featured such an odd quarterback benching was in the middle of the 1987 season, when the Washington Redskins' Jay Schroeder returned from a shoulder injury just months after leading the team to the NFC championship game. He was nonetheless replaced by Doug Williams, who led the Redskins to a Super Bowl championship.
Schroeder, who is now the head coach of the Village Christian High football team in Sun Valley, still remembers the frustration.
"It's extremely difficult, because you are doing what they asked you to do, and you are doing it well, and then…" he said in a phone interview. "It's a tough situation. Life is not fair. A lot of things aren't fair."
So in this biggest of football weeks, while his coach, Jim Harbaugh, is being praised for such a gutsy decision, and while Kaepernick is being hailed as the new big thing, Alex Smith has disappeared. Or has he? In some ways, the Super Bowl scrub is more visible, more accurate, more effective than ever.