The NFL cited "integrity of the game" as the main reason for the rule change, which follows the San Francisco 49ers' debacle in January's NFC championship game, where they lost their starting and backup quarterbacks with injuries and were ultimately crushed 31-7 by the Philadelphia Eagles.
According to the updated bylaw, teams may designate the third quarterback if he is included on their 53-man roster, as practice squad players will not be eligible even if they are elevated to the active roster during the week of the game.
Furthermore, the third quarterback will not count as one active player on game day, but will only be allowed to enter the game due to injury or ejection of the other quarterbacks and not by technical decision.
The NFL had already implemented this rule between 1991 and 2010.
