When Sam Bradford, my 2nd string QB, went down, I took a gamble. Hope Sam is back up for this weekend. My first pick, Andrew Luck, is still out.
Man, that's a tough situation there.
I always had luck with picking up a solid player against a really bad pass defense, or a young QB on a team likely to get blown out.
First is more conservative, but generally you'll get a couple touchdowns and 200 yards out of a mediocre vet QB playing against a ****** d. Second is much riskier but you also give yourself a chance that a guy throws 50 passes bc they're down all game and gets 300+ 3td and a pick or two. If it's a young guy drafted high they usually won't pull him but there's always a chance he's the reason they're losing so badly.
Tough getting in a pinch with QBs, at the other spots there's more backups to try and less screwups to deal with. Good luck.