After holding teams without a rushing touchdown through the first ...

AP FILE PHOTO, DEC. 4, 2011 | published: December 19, 2011

After holding teams without a rushing touchdown through the first 13 weeks — one game shy of the NFL record — the 49ers’ defense will get a big test from Pittsburgh RB Rashard Mendenhall (34) and the rest of the Steelers tonight in a game overfl owing with playoff implications.