Saw a tweet the other day from one of the local Steelers media, can't remember which one off the top of my head but it talked about how the Steelers were dropping Lamarr Woodley in coverage much more than we might have anticipated.
It basically said that up until the last minutes of the game, Woodley had only actually rushed Peyton Manning 4 times and the rest he was dropping back in coverage. The last 10 minutes he did rush him 6 more times for a total of 10.
Seems to me that if Harrison is out and Woodley is your best pass rusher then you might want to actually put him in situations where he can rush more. I get that Worilds and Carter are coming back from injury and inexperienced respectively but man you aren't going to get sacks by keeping your best guy in coverage all day long.