Steelers safety Troy Polamalu suffered a serious knee injury last season, one that he worried might end his career. "Yes, it was a concern," said Polamalu. "The hardest thing was if I would have injured it again, the doctor was saying that it will be a career-ending injury, most likely. "I had to face that." Polamalu was forced to wear a brace when he did play last season, something he was reluctant to do. "In the past, I had to wear a brace because it was career-threatening. A career-ending injury if I would have sustained another injury," said Polamalu, explaining why he didn't play down the stretch last season.