PITTSBURGH -- This might be the first time Troy Polamalu is happy to hear that an injury will keep him out from three to six weeks.
Polamalu realizes his injury could be much worse. Maybe even Brian Urlacher-like worse.
The two-time All-Pro safety doesn't need surgery to repair the tear in his left medical collateral ligament that occurred during a scramble for the ball on a blocked-field goal attempt Thursday against Tennessee. Coach Mike Tomlin's preliminary estimate of how long Polamalu will be out also hasn't changed.
"Regarding an injury to the knee, this is the best-case scenario," Polamalu said as the Steelers returned to practice on Monday. "There's no question that I'm very blessed that this scenario has come about rather than any worse scenario."
For now, Polamalu will rest, and hope there are no complications in his recovery -- just as there weren't when he needed only three weeks to return from a sprained left knee in 2007.
Still, Polamalu's injury means the Steelers (1-0) and Bears (0-1) will be without two of the NFL's best defensive players Sunday in Chicago. Urlacher dislocated his right wrist Sunday night against Green Bay and is out for the season.
No matter how long Polamalu is sidelined, his absence will be a setback for what was the NFL's best defense the last two seasons. Polamalu's ability to adjust positions from play to play, his speed and his ability to be a pass rusher and pass defender makes him one of the NFL's most versatile players.
"We're going to miss him. There's only one Troy, not just on this team but in the whole NFL," Steelers safety Ryan Clark said. "There's plays he can make that nobody else can make. I would be foolish to say to you guys (reporters) it won't be different without him, and you guys would be just as foolish to print it."
Polamalu was injured when Titans tight end Alge Crumpler fell on him after Aaron Smith blocked a Rob Bironas field-goal attempt in the second quarter. Asked if it was normal to be on special teams, Polamalu said, "Our defense is always (out on a field goal attempt), our whole defense."
Polamalu will be replaced by Tyrone Carter, who is in his ninth season and sixth with Pittsburgh, partly because he can fill in at both safety positions. Carter made five starts in 2007 when Polamalu last hurt his knee.
Outside linebacker LaMarr Woodley will be surprised if defensive coordinator Dick LeBeau makes numerous changes to adjust to being without Polamalu, who had six tackles and an interception in less than a half against Tennessee.
"I think we'll continue to do what we've been doing," Woodley said. "We don't want to change up everything because then we're not that same physical defense that we've always been. Troy's definitely a good player, and we've lost a good player for a few weeks, but the guy behind him is going to step up and do an excellent job as well."
"Troy's the best safety in football and, when you lose a guy like that, it's hard," Clark said.
Copyright 2009 by The Associated Press