Roethlisberger, who won Super Bowls with Pittsburgh in 2006 and 2009, said he was anxious to get back on the field after uncomfortably watching his team mates from home.
"I have no fingernails left," Roethlisberger told reporters on Monday. "It was hard, it really was, to watch them at home. I was on the edge of my chair, trying to keep busy. It was tough, but it was fun watching them win."
The quarterback was accused in March of sexually assaulting a 20-year-old female college student in a nightclub. He was not charged with a crime but NFL Commissioner Roger Goodell said he still violated the league's personal conduct policy.
During the suspension, Roethlisberger was not allowed to be at the team's practice facility, attend games, represent the club publicly or have contact with any member of the coaching staff or other football operations personnel.
The Steelers (3-1) were denied a 4-0 start to the season when the Baltimore Ravens scored a game-winning touchdown in the final minute of Sunday's game.
Pittsburgh's next game is October 17 against Cleveland.
(Reporting by Frank Pingue in Toronto)