Panthers exercise fifth-year option on WR Kelvin Benjamin

CHARLOTTE, N.C. -- Concerns over weight didn't prevent the Carolina Panthers from exercising the fifth-year option on wide receiver Kelvin Benjamin as planned, league sources told ESPN.

The move came three days after Carolina coach Ron Rivera shot down a report that the 28th pick of the 2014 draft was close to 280 pounds.

But Rivera said for the second time in three offseasons that Benjamin, listed at 6-foot-5 and 243 pounds, is overweight, and he expressed concern.

"He is a little heavy. He knows it. We've talked about it,'' Rivera said Saturday in a draft wrap-up news conference. "We've talked about what he has to do. He's done a great job in the two weeks he's been here.

"Am I concerned? Yes. He is heavy. I'm going to admit that right now. But is he working hard? Absolutely.''

Rivera said during the 2015 offseason that Benjamin reported to offseason workouts overweight. He speculated that the extra weight may have contributed to two hamstring injuries during workouts.

Benjamin's 2015 season ended prematurely when he suffered a torn ACL in training camp. He opened the 2016 season strong, but his production dropped off midseason in part because of conditioning and soreness in the knee.

Benjamin led all Carolina wide receivers with 73 receptions and 1,008 yards during his rookie year and 63 receptions and 941 yards this past season.

The Panthers used their first two picks in last week's draft to add more speed at receiver in Stanford running back/slot receiver Christian McCaffrey and second-round pick Curtis Samuel, a wide receiver out of Ohio State.

Rivera said when the team is allowed under the collective bargaining agreement to set player weights, he'll do that, and Benjamin will be held accountable.

"The guys will follow the rules like they always do and guys will be punished accordingly to what's allowed,'' Rivera said. "The biggest thing is being ready for minicamp. Once we start with the OTAs, we'll work toward minicamp.''

ESPN's Adam Schefter contributed to this report.