Clabo was part of an offensive line that helped the Falcons finish second in the NFL with an average of 152.7 yards rushing per game.
In other moves, the Falcons signed free agent wide receiver Bradon Godfrey and released linebacker Brock Christopher .
BROWNS: Wide receiver Donte' Stallworth pleaded not guilty to DUI manslaughter charges from a fatal Miami car crash in which a pedestrian died.
The 28-year-old Stallworth did not appear in court. A trial date has not been set. He faces up to 15 years if convicted.
PATRIOTS: Running back Patrick Pass , a former Georgia standout who won three Super Bowls in seven seasons with the team, has signed a contract to return
STEELERS: QB Ben Roethlis-berger returned to practice a day after he limped off the field following a collision with running back Willie Parker . Roethlisberger had his left knee wrapped.
JAGUARS: Two-time Pro Bowl defensive tackle John Henderson wants to make it clear: He's not faking an injury, he's committed to the team and eager to return to form. Henderson is out because of a dislocated shoulder.
CARDINALS: Signed two-time Pro Bowl safety Adrian Wilson to a new five-year contract that runs through the 2013 season. Terms of the deal weren't disclosed.
49ERS : Signed left tackle Joe Staley to a six-year contract extension, securing their durable young lineman through 2017.
SUIT SETTLED: The NFL Players Association reached a $26 million settlement with retired players who had successfully sued the union for cutting them out of lucrative marketing deals.