Game-day QB dynamics change with rules

SAN FRANCISCO -- The St. Louis Rams went into their regular season with only two quarterbacks on their 53-man roster.

The Arizona Cardinals, San Francisco 49ers and Seattle Seahawks named their third quarterbacks inactive Sunday.

Rules changes allow teams to keep 46 players active on game days without a special designation for third quarterbacks. As expected, teams aren't valuing third quarterbacks enough to keep them active at the expense of players more likely to get into games.

The tradeoff is an unlikely one: having to play a non-quarterback under center after losing both quarterbacks to injury during the same game.

Receiver Early Doucet would likely be the emergency quarterback for Arizona. Fullback Michael Robinson is among those in Seattle who might qualify for the role, with running back Leon Washington as another candidate. I'm not sure who would fill the role for the 49ers. Josh Morgan and Ted Ginn Jr. come to mind. Fellow receiver Michael Crabtree played quarterbac in college.