According to Ed Bouchette of the Pittsburgh Post-Gazette:
#Steelers Ben Roethlisberger has a rare rib injury that could kill him by pressing against his aorta. Too big risk. Has to wait until heals— Ed Bouchette (@EdBouchette) November 14, 2012
This isn't a matter of toughness or determination, as it usually is with Big Ben; rather it's a matter of life and death. Neither he nor the Steelers will push for an early return, and it could be a long time before he's cleared for contact.
Given the rarity of this injury (doctors say the last one on record was in 1998, when a rugby player suffered the same injury; h/t Pittsburgh Post-Gazette), it's safe to say we can operate from the perspective that Roethlisberger may not play at all the rest of the way.
Assuming he won't return, the Steelers still have the pieces in place to earn a playoff spot.
Byron Leftwich isn't nearly as good as Roethlisberger, but he is a capable backup with plenty of experience. Remember, he was the franchise quarterback of the Jacksonville Jaguars for four-plus years, and he compiled a record of 24-20 during that time.
Throughout his 10-year career, Leftwich has proven he's a good decision-maker, throwing 58 touchdown passes and 41 interceptions. He isn't nearly as accurate as Roethlisberger, but he won't lose games for the Steelers by turning the ball over.
With him behind center, the Steelers must pound the ball with their talented trio of running backs—Rashard Mendenhall (who is set to return to the starting lineup in Week 11, per Gerry Dulac of the Pittsburgh Post-Gazette), Isaac Redman and Jonathan Dwyer.
As long as the running game continues to improve (140 yards per game the past four games), Leftwich's responsibilities won't overwhelm him, and the Steelers will be just fine on offense.
On the defensive side of the ball, the Steelers continue to amaze me by smothering opponents' passing games, holding teams to just 171 yards per game (No. 1 in the NFL)—without Troy Polamalu, no less.
This defense is almost as impressive against the run, holding opponents to just 95 yards per game, good for No. 6 in the NFL.
Without Roethlisberger, the Steelers will just have to win games the old-fashioned way—with a pounding running game and a dominant defense.
The team has a favorable schedule, too, with five of its seven remaining games coming against teams with a losing record. Furthermore, the AFC is particularly weak this season outside of the top six teams (all of which have a record of 6-3 or better), with every other team posting a record of 4-5 or worse.
Odds the Steelers make the playoffs: 3/1