Patriots backup QBs played key role in Super Bowl run (The Associated Press)

Being a backup quarterback for the New England Patriots during Tom Brady’s tenure has typically been a practice-only position. With the exception of the 2008 season when Brady missed the final 15 games after suffering a season-ending knee injury in the Patriots’ season opener, he started all but two of New England’s regular-season games from 2001 to 2015. Matt Cassel did his best in Brady’s absence in 2008, but came up short of leading the Patriots to the playoffs that season.
Source: Yahoo.com