"In an interesting way, this might have been the best thing to happen to him in terms of his pure quarterbacking development," Rivera said following Thursday's practice. "He's had to stay in the pocket. He's had to have good footwork. He's had to step into his throws."
In other words, Newton has had to rely on his arm and the mental aspects of his game more so than his legs, which have made him such a dual threat.
That is key, because there will come a time when Newton no longer can depend on his scrambling the way he has during his first three NFL seasons.
Rivera used former NBA star Michael Jordan, the owner of the Charlotte Hornets, as an example.
"Michael Jordan used to go to the hole all the time and dunk, make spectacular layups and stuff like that," Rivera said. "But if you ask Michael, he learned that later in his career he had to develop that jumper. So he went to work at it.
"Cam's the same way. He knows he's got to develop as a passer."
But for now Newton's legs remain a weapon. And in the mind of Rivera, the left ankle that was surgically repaired in March is 100 percent.
"He's really close, and I think he thinks he's really close," Rivera said as he looked ahead to Friday night's exhibition at New England. "But when he all of a sudden cuts it loose and let's it go, that'll be enough to convince me."
The Panthers have kept Newton on a tight leash when it comes to scrambling and running the read option during training camp. But when the first pick of the 2011 draft spun out of trouble under pressure in Sunday's 28-16 victory against Kansas City, Rivera took that as a positive sign.
Does that mean Rivera is ready to turn Newton loose against the Patriots? Not entirely. He will still yell at his franchise quarterback to go down if Newton scrambles.
But Rivera won't complain if Newton takes off for a positive gain, understanding the positive psychological impact that could have.
"He has to do what he has to do to protect himself," said Rivera, who plans to play Newton in the first half. "He has to do what he has to do to make plays. If he runs, it's a great sign and I'm fine with that."
Just don't expect Newton to slide to protect himself.
"I'm not a sliding type of guy," Newton said. "I get down the best way I know how. I really wasn't good at baseball."