Flag football, that is.
Smith was injured Sunday while playing in a flag football game. It's an activity that could violate the terms of his contract, although Smith is expected back before the start of the regular season and may avoid serious punishment by the team.
The four-time Pro Bowl selection will be sidelined for at least the first couple of weeks of camp, but is expected to be ready for the opener Sept. 12 at the New York Giants.
"They were messing around, the ball went over his head and he slipped," said Smith's agent, Derrick Fox. "He put his arm out to brace himself. When he did he felt a sharp pain. He went in [Sunday] afternoon to have an X-ray and it showed a break."
Smith had surgery Sunday night to have a small plate and screws inserted in his arm. Fox said while it's the same arm he broke at the end of last season, it's in a different spot and not his wrist. Smith suffered no nerve damage, is expected to make a full recovery and could return as soon as midway through the preseason.
"I'm not trying to play doctor, but I don't think he'll miss any games due to this injury," Fox told ESPN NFL Insider Adam Schefter.
Smith annually hosts a youth football camp in Charlotte which began Thursday, the day after the Panthers concluded voluntary spring workouts. Fox initially said Smith was injured playing with children at his camp, but later said he was unsure if he was playing with children or adults.
Smith's youth camp ended on Saturday, a day before he was injured.
Former Panthers quarterback Josh McCown told The Charlotte Observer he has played with Smith a few times in an adult flag football league at a Charlotte YMCA, but wasn't with him on Sunday.
Standard NFL contracts bar playing football outside of team settings and ban other risky activities, but Fox said he didn't believe the Panthers would take action since he should be healed for the regular season.
Panthers general manager Marty Hurney didn't return a phone message from The Associated Press seeking comment, but did release a statement.
"Steve talked to me and he feels terrible about it," Hurney said. "Now his focus is on rehabilitating process and getting back as quickly as he can."
The 31-year-old Smith ranks first in team history with 58 touchdowns and 32 games of 100 or more yards receiving. Smith, who led the NFL in catches, yards receiving and touchdown catches in 2005, had 65 catches for 982 yards and seven touchdowns in 15 games last season.
His absence from the start of camp on July 28 will coincide with major changes made at quarterback for Carolina. The Panthers released longtime starter Jake Delhomme, promoted Matt Moore to starter and drafted Jimmy Clausen of Notre Dame in the second round.
The Panthers also enter the season looking for a No. 2 receiver after Muhsin Muhammad wasn't re-signed and then retired.
Information from ESPN NFL Insider Adam Schefter, ESPN.com's Pat Yasinskas and The Associated Press was used in this report.