Aaron Smith
Aaron Smith With five-time Pro Bowl safety, Troy Polamalu finally returning to the practice field, the Pittsburgh Steelers were dealt another crushing blow to their defense when they announced that defensive end Aaron Smith would be lost for the season with a torn rotator cuff in his right shoulder.

The Steelers officially placed Smith on the IR on Wednesday and will have to scrambled to replace their the run-stopping defensive end.

Although Smith has been to the Pro Bowl just once in his 11 seasons, Pittsburgh players know that it's only because he his not as well-known nationally as Polamalu or linebacker James Harrison.

"A guy like that, I truly believe, is irreplaceable," Polamalu said. "There's a lot of other big role positions that get a lot of prestige, but who can always
be replaced, but it's always tough when it has to do with our line. I truly believe our defensive line controls the outcome of the game. It's big. It hurts us."

Smith rarely makes the high-impact plays that Polamalu does, but safety Ryan Clark said that Pittsburgh would not have been No. 1 in the league the last two seasons without him.

"Nobody's going to replace him," Clark said. "I think he's one of the unsung heroes in this league, a guy that's very under-appreciated for what he's done for many years."

Late in the 2007 season, the Steelers were No. 2 against the run before Smith tore a biceps muscle and was lost for the year. In turn, they gave up 629 yards rushing while losing three of their final four games.

This season, Smith has 13 tackles, two sacks and a blocked field goal. He is eighth in team history with 43 sacks.