Joe Namath calls out Geno Smith for not playing through injury

New York Jets quarterback Geno Smith started his first game of the season Sunday, but didn't last long.

Smith injured his knee in the first half and exited the game, ceding the starting job back to the recently benched Ryan Fitzpatrick. Smith went to the locker room before returning to watch the second half in street clothes.

Nothing about that is particularly unusual, but it didn't sit well with legendary Jets passer Joe Namath:

Sound familiar? Chicago Bears quarterback Jay Cutler was widely criticized for leaving a 2011 playoff game with a knee injury and then watching the rest from the sideline.

Why some people - even former players like Namath - have a hard time believing it's possible to suffer a knee injury that prevents one from playing football (which requires a high degree of mobility) but isn't severe enough to prevent you from standing is a bit of a mystery.

Not every injury is black or white, as one can "walk off" both a torn ligament and a minor sprain. There are shades of grey.

Surely Smith would remain in the game if it were possible for him to play through the injury. And surely he wouldn't be permitted to stand on the sideline if he were at any risk of worsening his injury by doing so.