Polamalu is "encouraged" by an MRI test he had on Tuesday, but he doesn't anticipate practicing this week. Asked if he needs a week of practice before playing again, he said, "I would think so."
The five-time Pro Bowl safety has missed nine full games and most of two others with separate ligament injuries in his left knee. He hasn't played since the opening series against Cincinnati on Nov. 15, though he has been working out in anticipation of a return.
"I've tried everything -- running, lifting, rehab," he said Wednesday.
Last week, Polamalu said he hoped to play Jan. 3 in the regular season-ending game in Miami.
Since Polamalu sprained his posterior cruciate ligament, the Steelers (7-7) have won only one of the six games he hasn't finished. They were 2-2 when he missed four games early in the season with a sprained anterior cruciate ligament.
Without Polamalu, the Steelers defense has lost leads in the fourth quarter six times, and they recovered to win only one. Polamalu leads the Steelers with three interceptions despite playing only three full games all season.
"I don't believe that at all," Polamalu said, when asked if his absence is hindering the Steelers' ability to close out games. "I've been part of a lot of defenses here, defenses that lost games in the fourth quarter. I don't think one man makes that big of a difference. There's not one player who is irreplaceable."
The Steelers ended a five-game losing streak Sunday by beating Green Bay 37-36, despite twice giving up the lead in the fourth quarter. The comeback victory kept their modest playoff hopes alive.
"I think everybody feels a little better this week," Polamalu said. "We've got to get our confidence back, get in those situations and win in those situations."