The Pittsburgh Steelers have lost star defensive end Aaron Smith for the rest of the season with a torn biceps sustained in Sunday's blowout loss to the New England Patriots. Coach Mike Tomlin revealed the injury at his Tuesday news briefing. The injury is not expected to be career threatening, Tomlin said. Smith was placed on injured reserve, a move that means he cannot return this season. Defensive lineman Ryan McBean was promoted to the 53-man roster. "Being the guy he is, he continued on," Tomlin said Tuesday. "He came out a few times, and that was worrisome because this guy doesn't come out of games." The Steelers are already playing without starting safeties Ryan Clark, who was placed on injured reserve earlier this season, and Troy Polamalu, who has missed the last three games. The additonal loss of Smith, one of the best two-way defensive ends in the league, is a significant blow to the NFL's top-rated defense.