On Monday, the NFL owners approved a rule that makes a subtle change to the rule regarding the designation of a third quarterback on the game-day roster.
The change will allow a team to designate an emergency third quarterback for the game and would allow them to be activated during the game if the team’s two primary quarterbacks are injured and unable to play. This would not apply to a quarterback being benched.
In simplest terms, this rule change allows teams an extra roster spot that can only be utilized for an emergency quarterback. If a team loses both quarterbacks to injuries, that third quarterback is called into action and can play. But this only matters if both quarterbacks are injured. If the second quarterback is hurt and the emergency quarterback goes in but the injured quarterback is cleared to return, the emergency quarterback much leave the game at that point.
This is a rule that actually existed in the NFL from 1991 to 2010 to the league is just bringing it back.