Steelers have been hit hardest by injuries

There is a strong possibility that the Steelers have lost running back Rashard Mendenhall for the rest of the season. A source told ESPN's Adam Schefter that the team fears Mendenhall has torn his ACL and will have an MRI today to confirm that.

You can only assume coach Mike Tomlin shrugged his shoulders and said to himself: "What else is new?"

Many of the playoff teams are dealing with injuries (Houston is on its fourth quarterback of the season), but no one has been hit more widespread than the Steelers.

Mendenhall joins backup running back Mewelde Moore (sprained MCL) on the sideline. Starting quarterback Ben Roethlisberger is still hobbled by a high-ankle sprain and can't step into any throws. On the offensive line, Pro Bowl center Maurkice Pouncey returned after missing a game with a high-ankle sprain but left guard Doug Legursky has been out with a shoulder injury. Third receiver Emmanuel Sanders had missed five of the previous seven games with foot and knee injuries before playing Sunday.

On defense, six starters in the front seven have been sidelined at least one game. Only linebacker Lawrence Timmons has remained unscathed. Pittsburgh's two top pass-rushers, James Harrison and LaMarr Woodley, haven't played a full game together since Sept. 25, a Week 3 game at Indianapolis. That's all in addition to two head injuries suffered this season by Pro Bowl safety Troy Polamalu.

The result: the second-most wins in the AFC and the NFL's No. 1 ranking in defense.