Fantasy Football Championship week...QB situation?

I'm struggling on who to start as my QB for the last week of the season. I have Philip Rivers and Matt Schaub. Rivers is up against Washington while Schaub has New England. The Redskins are the worse team out of the two, but I have no clue how much playing time Philip Rivers will get since they already secured a playoff spot (home field adv. I believe). Schaub is playing against a better team, but New England also has made it into the postseason so they may pull some starters. Who do I go with? Thanks for the advice.