Brad Biggs at the Chicago Tribune accurately makes this prediction:
“The Bears cannot stop the run effectively in their base Cover-2 defense. With seven defenders in the box, they are getting overpowered. Injuries certainly play a big part in it and you have to imagine the St. Louis Rams are fixing to get rookie Zac Stacy going this Sunday at the Edward Jones Dome. [Baltimore running back Ray] Rice was the fourth back in the last five games to top 100 yards vs. the Bears and in the other game Alfred Morris had 95 yards on 19 carries in a game in which the Redskins amassed 209 yards rushing.”
What's worrisome is that the Bears have largely cleaned up their fundamentals. They're tackling better and as far as I can tell their run fits are reasonably good most of the time. I don't think there's a lot more they can do about this other than live with it and try to work around it. Not good.