PITTSBURGH — Steelers star safety Troy Polamalu hasn’t been ruled out of Sunday’s game at Kansas City despite injuring his left knee for the second time this season, though coach Mike Tomlin says he is questionable “at best.”

Polamalu, a five-time Pro Bowl player, missed four games earlier this season with a medial collateral ligament tear. He strained the posterior cruciate ligament while tackling running back Cedric Benson on Cincinnati’s first possession Sunday and did not return.

The latest injury is not as bad as initially feared, Tomlin said, because it did not affect the previously injured ligament. However, it seems likely the Steelers won’t rush back one of the NFL’s most versatile defensive players and will sit him out at least a week.

Polamalu missed five games with knee and rib injuries in 2007 but played every game last season as the Steelers won the Super Bowl.

Copyright 2009 by The Associated Press