The Giants' backup quarterback plan seems largely irrelevant because Manning has started 130 consecutive games (counting postseason) and has proven to be the most durable starting quarterback in the league. Should the unthinkable happen, the best thing the Giants could say about it is that they'd be replacing one former No. 1 overall draft pick with another. David Carr, who was drafted first overall by the Houston Texans in 2002, was 22-53 as the starter for the expansion Texans from 2002-06 and 1-3 in a brief stint as the Carolina Panthers' starter in 2007. He hasn't started a game since 2007 and has attempted only 58 passes (35 complete, three for touchdowns, one intercepted) over the past four seasons. He was Manning's backup in 2008, 2009 and 2011, so he knows the offense and the receivers. But a prolonged injury to Manning would be the worst conceivable circumstance for the defending Super Bowl champs.
Confidence rating (out of 100) if Manning goes out for extended period: 43.