Coach Bill Cowher yesterday pronounced safety Troy Polamalu "OK" and upgraded the injury status of two other players as the Steelers finished their final full practice in preparation for the Super Bowl. Polamalu, placed on the injury report Thursday with an ankle injury, practiced yesterday, although he left drills 30 minutes early. Fullback Dan Kreider (knee) and backup defensive end Travis Kirschke (ankle) practiced and were upgraded to probable. Cowher said a magnetic resonance imaginc scan on Polamalu's injured ankle Thursday showed no damage. Polamalu left practice Thursday when the ankle was injured and was listed as probable for the game . "Everything came back negative ... or positive, from our standpoint," Cowher said before practice. "There is nothing really there. We'll see how he feels today and monitor how much he does today. He should be fine for Sunday."