The NFL is a QB-driven league, but unfortunately, nothing lasts forever. These six teams need to draft a successor in 2017. 1. Cardinals: Carson Palmer likely only has a year or two left, so it's time to look for his replacement. 2. Saints: Drew Brees has said he can play until he's 45, but he only has one year left on his contract. 3. Giants: Eli Manning's play fell off a bit in 2016, and New York doesn't have a viable long-term replacement. 4. Steelers: Ben Roethlisberger mulled retirement after the season, so the end of his reign in Pittsburgh could come soon. 5. Chargers: Philip Rivers is 35 years old, and although he's never missed a start, San Diego needs to start thinking about its future. 6. Chiefs: Alex Smith still has plenty of gas left in the tank, but he isn't a true franchise quarterback.