Beason -- who ruptured his Achilles' tendon in Week 1 of last season -- participated in team drills for the first time this spring after being limited to individual drills and walk-throughs during organized team activities.
Who's next in line?
"Really, the biggest thing was just his conditioning," Rivera went on. "He was winded. He's done all the installation stuff. But he was out there. And you could see he had a little adrenaline rush going. He was all fired up to get that last extra set of reps. He (asked) out just because he was gassed."
Having Beason on the field had to be a big lift for the Panthers, who were forced to play the majority of last season without the quarterback of their defense. Rivera said Beason's interception of Newton provided a glimpse of his special skill-set.
"A natural play," Rivera said. "Somebody else might not make that play. But I think guys with his kind of his experience and his kind of ability make that. And that's what he saw. He made a nice move on the ball and a nice play."