Browns offensive tackle Ryan Tucker was suspended on Friday for the first four games of the season for violating the NFL's steroid policy.
Tucker, one of Cleveland's leaders on the field and in the locker room, missed part of last season with what the team called a "mental disorder."
He says he is now healthy and is eligible to return to the roster Oct. 1, one day after the Browns host the Baltimore Ravens.
"I didn't intend to compromise the integrity of the NFL or my team," Tucker said following Friday's morning practice. "I want to apologize to the fans, my family. It's been a long road. I was pretty down and out last year and in my attempt to come back I took a banned substance. I'm going to fulfill this punishment and get it behind me."
Tucker will be allowed to stay with the Browns during training camp and preseason.
However, coach Romeo Crennel said the 32-year-old player may not participate in team activities once the suspension without pay starts Sept. 1.
Tucker won a Super Bowl ring with the St. Louis Rams and has been a rock at right tackle for the Browns since joining them as a free agent in 2002. The 11-year veteran started all 16 games in 2005 and in 2003 he was the only Cleveland offensive player to be on the field for every snap.
He talked about "getting the respect and trust back of my teammates" earlier this week.
Tucker was placed on the reserve non-football-illness list for the final eight games last season.
At the time, the Browns said Tucker's disorder was one "commonly experienced by the general population as well as by professional athletes."
Tucker has given no details about his illness.
"I didn't know if playing again was a possibility," he said. "The bottom line is I'm healthy now, my family's healthy and happy, people are behind me here and my family's behind me."