Clark will head back to where he made his first NFL start, the Redskins, having signed a deal there in free agency Monday.
Washington signed Clark to an undisclosed contract, but he said multiple times he wasn't looking to sign a veteran minimum deal.
A team captain, Clark leaves Pittsburgh two years after a Pro Bowl berth, the first of his career, and a strong enough career in Pittsburgh to earn consideration among the best free agent signings in team history.
Comments he made after the 2013 season when his contract expired suggested Clark was not coming back - comments that included the frequent use of marijuana among players in the league.
He was never one to bite his tongue. Clark was seen as the vocal piece of the Steelers' defense as it navigated through the new concussion era in the NFL.