Coach John Fox said Hartwig would undergo surgery soon to repair a groin injury that kept him out of all but two games this season.
"We could have waited until the end of the season to have surgery. Now we've decided it just wasn't coming along, so he'll have it now," Fox said.
The Panthers gave the former Titan a five-year, $17 million free-agent deal in the offseason -- one of the richest contracts for a center in the NFL -- to replace the aging Jeff Mitchell, who wasn't re-signed.
But Hartwig missed a portion of training camp after undergoing hernia surgery and then strained his groin in the season opener against Atlanta. After sitting out six games, he played sparingly against Dallas on Oct. 29. He then reinjured the groin lifting weights a few days later and hadn't played since.
Two weeks ago, Hartwig said he believed the groin injuries were related to the hernia and said he was contemplating surgery.
"He came in here with big plans in terms of contributing but just never got healthy," Fox said. "Now we just have to get him healthy for next year."
Second-year pro Geoff Hangartner has filled in at center and the offensive line has improved of late. Carolina rushed for a franchise-best 242 yards last Sunday against St. Louis.
The Panthers signed receiver Taye Biddle off the practice squad to replace Hartwig on the active roster. Tackle Sam Wilder was signed to the practice squad.
Also Friday, running back DeShaun Foster (elbow), cornerback Ken Lucas (hamstring) and guard Mike Wahle (shoulder) all returned to practice after sitting out Thursday's workout. All three players remain questionable for Sunday's game at Washington.