The Redskins' backup quarterback right now is Rex Grossman, who was their starter last season, and is 27-24 as an NFL starter, postseason included. Grossman's best season was of course the year he quarterbacked the 13-3 Chicago Bears into the Super Bowl, but even that season he threw 20 interceptions to go with his 23 touchdowns. He threw 20 more interceptions in 13 games as the Redskins' starter in 2011, and in his career he has thrown 60 against only 56 touchdown passes. The good thing about Grossman, from the Redskins' standpoint, is that he knows the offense extremely well and operated it productively last season in between all of those interceptions. He should be able to help Griffin get a handle on the terminology and tutor him on game situations. The Redskins drafted Kirk Cousins in the fourth round this year thinking he could develop behind Griffin and Grossman, and eventually be a valuable backup or trade chip. But as of now, if Griffin went down, the turnover-prone Grossman would be the one to replace him. Again, at least Grossman knows the offense.
Confidence rating (out of 100) if Griffin goes out for extended period: 63.