Another Carolina Panthers offensive lineman is leaving the game on his own terms. Veteran guard/center Geoff Hangartner, who had three stints with the Panthers, told the Observer on Tuesday he is retiring after nine seasons. Hangartner’s decision follows the retirement of Pro Bowl left tackle Jordan Gross, who stepped down two weeks ago after an 11-year career. It’s not unexpected: Hangartner, who turns 32 this month, was cut by the Panthers last August before returning in November after a spate of injuries to their guards. “I’ve known for a while I was going to retire. I knew when I came back this was going to be my last year,” Hangartner said in a phone interview from Texas. “It was a good way for me to end because I got to come back and play for a team I loved playing for and finish out with my buddies. Luckily we had some success, which made it even more fun. It was a fitting way for me to end my career.” With Hangartner retiring, the Panthers have 17 players set to become unrestricted free agents when the league year begins at 4 p.m. Tuesday. Hangartner, the Panthers’ fifth-round pick in 2005, played 118 career games, with 85 starts. He was a rookie on the 2005 team that advanced to the NFC Championship Game, started eight games on the ’08 playoff team and played in eight games this past season as Carolina snapped a five-year postseason drought. Hangartner spent seven seasons with the Panthers, sandwiched around a two-year stint with Buffalo.