"He's done. He told all of us," tackle Max Starks told the Pittsburgh Post-Gazette.
The Steelers have yet to make an announcement regarding Hartings' status, though the center admitted in the final weeks of the season that he was likely finished.
Hartings was picked for the Pro Bowl after the 2004 and 2005 seasons and made the AP All-Pro team in 2004. He was the Steelers' starting center from 2001-06, replacing longtime star Dermontti Dawson, a Hall of Fame candidate.
Hartings was a first-round draft pick by Detroit in 1996 out of Penn State, and played guard with the Lions before being moved to center by Pittsburgh, which signed him as a free agent.
Hartings had never before played the position, but settled in well. Ongoing knee problems nearly caused him to retire before this season, but he returned to try to help the team defend its Super Bowl championship.