If I were Pittsburgh, here is what I would be worried about.
Pittsburgh's Offensive Line vs. Green Bay's pass rush. They were decimated with injuries before yesterday. If Puncey can't play, Big Ben might take a vicious beating.
Pittsburgh's CB vs. Donald Driver, Greg Jennings, Jordy Nelson. That might cause some real problems.
If I were Green Bay, here is what would concern me.
Green Bay's running game vs. Pittsburgh. They will need to at least keep Pittsburgh honest. If Starks and jackson can't get going, the play action pass won't fool anyone.
Troy Palamalou vs. the seam route. No safety reads and reacts to the seam route better than him. Rodgers is the best in the game completing the seam route, however, he hasn't faced a safety of Polamalu's caliber
Green Bay's Zone Blitz vs. Ben Roethlisberger. The Zone blitz brings pass rushers from every possible angle. However, with a zone blitz, if they don't get immediate pressure on Roethlisberger, he may be able to expose the middle of the field with their Tight End (Name escapes me), and with the amount of speed on the outside, Roethlisberger is at his best when the play breaks down, and has the ability to step up or step back in the pocket, and fling it 50 yards downfield. The speed of Pittsburgh's wide receivers could cause problems for the CB's if the play lasts more than 4-5 seconds.