Hangartner has started 83 games, including 12 last season for Carolina, during his eight-year career with the Panthers and Buffalo Bills.
The move was a bit surprising considering Hangartner had been running with the first team at camp, and the player Carolina drafted to eventually replace him -- Edmund Kugbila from Valdosta State -- has missed the majority of training camp with a pulled hamstring after sitting out OTAs with a knee injury.
Backup quarterback Derek Anderson called Hangartner one of the most popular players in the locker room, saying, "It's tough, but somebody is going to have to step up."
Hangartner was due to make $1.575 million this year.
Garry Williams, who has started 20 games in his first four seasons, is expected to step in and work with the first team at right guard -- at least on a temporary basis.
Williams started nine games last season for Carolina, most of those at right guard after the team was forced to move Hangartner to center because of a season-ending injury to Pro Bowler Ryan Kalil.
Jordan Gross, who has played six seasons with Hangartner, said he was surprised and saddened by the move.
"He got a text to go see coach [Ron] Rivera first thing in the morning, and that's never good news," Gross said. "Honestly, I was wondering if he was going to get traded to Denver, because they have a [injury] situation there. But yes, it surprised me."
Teammates often referred to Hangartner by his nickname, "Piggy."
Gross said it's a solemn reminder that the NFL is a business.
"You hope that management knows what they're doing and that it is for the better and it will make us a better team," Gross said. "That's really what we have to focus on."
The Panthers met with free agent guard Travelle Wharton a few weeks ago but have not signed him. The 32-year-old Wharton played for the Panthers from 2004-11, starting 99 games during that span before signing with the Cincinnati Bengals.