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
Tom Brady!
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
doug williams
69 Yards: NFL QB Challenge. (Donovan McNabb threw 76). 69 Yards: NFL QB Challenge. (Cade Mcnown threw 72).
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.