Troy Polamalu isn't certain if he will be back this season. Polamalu is hopeful of playing again, but he said Tuesday there is no definitive date for his return. Polamalu's latest injury, to his posterior cruciate ligament, was initially expected to be less severe than the anterior cruciate ligament injury that kept him out of the Steelers' second through fifth games. But he won't play Thursday night in Cleveland, the fourth consecutive game he's missed with his latest injury. "Honestly, I don't think one person would make a difference in how this season has ended up for this team," Polamalu said.