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. It was one of only two times since Brady became New England's starting quarterback that his team failed to make it to the postseason.
So when Brady decided before the season to end his legal...