Mahan, a six-year veteran, signed with the Steelers prior to the 2007 season as an unrestricted free agent from the Buccaneers, who selected him in the fifth round (168th overall) of the 2003 NFL Draft.
Mahan started all 16 games in the regular season and the Steelers' only postseason game in 2007. He was replaced in the starting lineup this offseason by street free agent Justin Hartwig.
Second-year center/guard Darnell Stapleton should expect to be active on game days as the primary backup to Hartwig.
The Steelers open their season Sunday at home against the Houston Texans.