Steelers' Troy Polamalu appears to re-injure calf

• Star safety leaves game vs. Eagles, questionable to return
• Injury has already cost Polamalu two starts this season

PITTSBURGH — Pittsburgh Steelers safety Troy Polamalu appeared Sunday to aggravate the right calf injury which forced him to miss the previous two games.

He played one quarter vs. the Philadelphia Eagles after being listed as probable with the injury, then limped off the field during the first half. He did not leave the sideline and his return is questionable.

Ryan Mundy has again taken over for Polamalu after being has stand-in the previous two games.

Polamalu first suffered the injury in last season's playoffs, and said he aggravated it during the week of practice ahead of Pittsburgh's season-opening game vs. the Denver Broncos.

Two other Steelers dealing with injuries returned to the starting lineup Sunday. James Harrison (knee) had yet to record a tackle after the first quarter, but Rashard Mendenhall (knee) scored a second-quarter touchdown on a 13-yard swing pass from Ben Roethlisberger to give his team a 7-0 lead.