Carolina Panthers starting defensive tackle Star Lotulelei is recovering from offseason surgery to clean up his shoulder.

Lotulelei's surgery had not been previously reported, but he is expected to be ready for the start of training camp next month, according to the Charlotte Observer.

The 27-year-old Lotulelei was on the sideline as the Panthers' three-day minicamp wrapped up Thursday. The team's 2013 first-round pick participated in position drills this week while being held out of scrimmage situations.

The 6-foot-2, 315-pound Lotulelei is set to earn $6.76 million in the final year of his rookie deal after the Panthers exercised his fifth-year option. He made 26 tackles and a career-high four sacks in 16 starts last season.