Wide receiver Cam Newton suffered a broken bone in his left arm - the same arm that he broke late last season - while playing flag football over the weekend.
He underwent surgery Sunday night. It is uncertain when Smith will return, but he will miss the start of training camp when the Panthers report to Wofford College on July 28.
"Steve has talked to me and feels terrible about it," said general manager Marty Hurney. "Now his focus is on the rehabilitating process and getting back as quickly as he can."
Smith fractured the radius bone in his left arm last year on a hit from New York Giants safety Michael Johnson as he was crossing the goal line with a 27-yard touchdown pass in a Week 16 game at New York. The injury caused him to miss the Panthers' regular-season finale. Smith led Carolina with 65 catches for 982 yards and seven touchdowns in 2009.
