Panthers coach Ron Rivera said Benjamin came in for treatment Monday morning on his left knee. Trainer Ryan Vermillion examined Benjamin and decided to send the team's first-round draft pick to Charlotte for the medical exam.
Benjamin did not participate in Monday's practice.
"It's strictly precautionary," Rivera said, adding that the team expects to hear the results later Monday.
Rivera said Benjamin knocked knees with another player on Sunday, but he still finished the practice.
"I'm optimistic," Rivera said. "He shook it off and he finished practice. It could just be one of those things where if he had iced it right away and not finished practice maybe it would have been better. If it's negative we'll just keep on rolling. I'm optimistic that is what it's going to be."
Benjamin has been working with the starters and is having an outstanding camp.
He has been catching everything in sight and trying to adapt to quarterback Cam Newton, who is coming off an ankle injury.
Rivera said Benjamin needs as many reps as possible being a rookie.
"He's had a great camp," Rivera said. "He came in in tiptop shape and ready to roll. He's one of those guys who spent time with Cam (before training camp) working out. It's one of those that we want to make sure and be smart about."
Benjamin was the 28th overall player drafted.
He caught 54 passes for 1,011 yards and 15 touchdowns last year for Florida State, including the winning touchdown against Auburn in the national championship.