Only one can be playing currently one the field but an unlimited amount of backup qb's can be on the side lines
Only one qb can bev playing on the field, but there may be multiple back up qbs.
1989 as QB started in one game after the original QB was suspended for gambling
Drew brees 7
No one
3rd string qb's are considered emergency qb's. If they enter the game before the 4th quarter begins, the starter and his back up can no longer return to the field.
Sid luckman, November 14, 1943
THE BACK UP
The cast of QB Game Analysis - 2009 includes: Josh McCown as himself Mark Robert Ellis as himself
Two. One as the starting QB for the Chicago Bears in Super Bowl XX and one as the backup QB for the Green Bay Packers in Super Bowl XXXI.
69 Yards: NFL QB Challenge. (Donovan McNabb threw 76). 69 Yards: NFL QB Challenge. (Cade Mcnown threw 72).
Donald Hollas
In general, 90 total -- 45 on each team. Each team has an active roster of 53 men, but must declare 8 men inelligible on game day. One of these is almost always the third string quarterback, who is subject to in-game promotion to active if, however if activated, both of the other QBs are then inelligible to return to the game. If a team has three QB on their 45-man roster, they aren't allowed to identify a "promotable" third QB.