Backup: Ryan Mallett

Best-case scenario: The Brady-Belichick duo adapts to losing Wes Weler and Aaron Hernandez, Rob Gronkowski gets (and stays) healthy, and the Patriots remain a contender. In other words, Tom Brady gives us reason No. 1,359 to hate him for haivng a better life than ours.
Worst-case scenario: Losing players like Aaron Hernandez and Wes Welker proves as costly as skeptics think and the Pats miss the playoffs for the first time since 2008. Bill Belichik has a Dennis Green-esque press conference meltdown that sets Twitter ablaze.