The Steelers practiced under cover yesterday because it rained, and then it poured injuries on them indoors.

Linebacker Joey Porter and cornerback Deshea Townsend left practice with hamstring injuries and coach Bill Cowher listed them as questionable for Sunday's game against Kansas City. It wasn't the preferred start to a week of practice for the defending Super Bowl champions who are trying to snap a three-game losing streak.

"I'm good," Porter said before he headed to the trainer's room to have his left hamstring injury evaluated. "I'm going to find out right now. I don't know the situation."

Glum was one way to describe much of the team's mood after the two injuries, although they did not express it outwardly. Adding to the problem of possibly losing a Pro Bowl outside linebacker, the Steelers already lost their top backup when James Harrison was ruled out this week because of a high ankle sprain.

That would mean if Porter cannot start, Arnold Harrison would. He spent his rookie season on their practice squad and was put on the 53-man roster for the Super Bowl because of an injury, but he did not play. He has played on special teams this season and one snap on defense Sunday night.

If Townsend cannot play, Bryant McFadden would start and rookie Anthony Madison, signed from the practice squad Saturday, would become No. 3.

"We have some young guys, but around here, when a guy goes down a new guy steps in," linebacker Larry Foote said.

Rookie Rian Wallace, an inside linebacker by trade, also can play outside linebacker and practiced there in training camp. He already was tabbed to replace James Harrison on special teams.

"Ah, man, that's the name of the business," Arnold Harrison said. "Football's a contact sport and it's made for tough people. You can be sitting there, not even on the team, at home and next thing you know you could be playing.

"Wilder things have happened than a backup linebacker winding up starting. I'm here to fill in when my name's called and I'm going to do the best job I can when the opportunity presents itself."

NOTES -- Starting guard Kendall Simmons also was added to the injury list yesterday after the heel of his left foot was burned during treatment, an unusual injury to be sure but not further explained by Cowher. ... The Steelers signed defensive end Junior Glymph, from Carson-Newman, to their practice squad and released Shaun Nua.