BACK WHEN THE conversation about NFL quarterbacks began and ended with Cam Newton, back when he was leading the Panthers to the Super Bowl and winning the league's MVP and causing a Concerned Mom to write a letter to the editor claiming the local quarterback's touchdown celebrations were sending her preteen daughter down the road to perdition -- way back then, when the idea of his Panthers' career ending with an ignominious outright release was unthinkable, his father interrupted the coronation with a prediction that seemed outside the moment.

It was a few weeks before Super Bowl L, and Cecil Newton's voice stormed through the phone with the strength of 20 brigades. "There's an audience waiting for him to lose so they can say, 'Now's our time to talk. He's had his time, now it's our turn,'" he told me. "We already know that's out there."

Cecil Newton wasn't referring to anything in particular -- no specific event or inevitable career arc that would spark his predicted response. He was talking about the general aura of Cam, and how all of it -- attitude, ability, flamboyance and yes, race -- tends to make a subset of the population lose it.

In fact, this law of action-reaction -- it's Newton's Third Law of Motion, for those seeking symbolism -- has been the central principle of Cam's career. It's been the throughline; he acts, whether with transcendent play or ostentatious celebration or mysterious pronouncements, and there is always an equal (at minimum) and opposite reaction.

But with Newton cast adrift after being sidelined for much of the past year, now it feels like the equation has been reversed. The actors are the Panthers, a rebuilding team with a new coach and the hope of a new identity, a team that is saving more than $19 million by shedding the defining player in franchise history.

Now we await Newton's reaction.

Newton's release came as no surprise, and in a business where ruthlessness is not only expected but rewarded, it was a call every team would have made. Newton has been on a gradual and painful retreat, from MVP at 26 to untradeable at 30. The details of the separation can be dissected -- last week owner David Tepper said the Panthers and Newton mutually agreed to pursue trade options; Newton said he agreed to no such thing -- but the result was predictable from the moment Newton's 2019 season ended after two games.

Now, of course, come the questions: How will Newton react? Is there a second act out there for one of the most dynamic athletes ever to play the most visible position in American sports?

There are barriers, not all of them self-inflicted. The NFL's decision to remain in business during the COVID-19 crisis has nonetheless kept teams from performing medical tests on prospective players, and even though Newton had a physical overseen by the Panthers and his agency, prospective employers might be wary of committing to a mobile quarterback coming off foot surgery. The timing of his release, coming after the great musical-chairs QB scramble, dramatically limited his options. He wants a new contract that extends beyond his current deal, which expires at the end of this season, and he presumably wants one that one that will pay him more in line with an MVP than a reclamation project.

He's had two shoulder surgeries, and he hasn't been the same since the first injury occurred in Week 13 of the 2016 season. Every statistic, both the advanced and the antiquated, dropped precipitously beginning with that injury. A pre-injury QBR of 58 declined to 47; 7.5 yards per attempt down to 6.8; over the past four seasons his QBR ranks 31st among 40 qualified quarterbacks. And then there's a stark number from the world's most unevolved stat: His team lost the last eight games he started.

Still, there's the action-reaction thing. He's only 30 years old. This lengthy layoff -- his last game was in September -- means he should be healthier than at any time since 2016. But his future appears to hinge on preserving that health, and preserving that health appears to hinge on taking fewer hits, which means taking fewer chances. It sounds simple, because it is. Yet, again, it leads to more questions: Is he capable of changing his style? And if he is, how good can a more judicious Cam Newton be?

There was a time when not everyone thought he could adapt to the NFL game, but he did. He came into the league amid questions about his desire; now-Raiders GM Mike Mayock famously said, "I think the kid is smart enough. I just don't know if he cares enough." Newton responded to that, consciously or not, by playing as if he were indestructible. He is the only quarterback to lead a franchise in passing and rushing touchdowns, but he also took 38% more hits than any other quarterback (1,235 to Russell Wilson's 972) from 2011 through 2018. He was sacked nearly 30 times a season and rushed 934 times, and his style always seemed to keep him from being afforded the same protection from officials as smaller quarterbacks. He played quarterback with the body of a 1970s defensive end -- he's the same size as Steelers great L.C. Greenwood -- and the speed of a wide receiver. My first thought when I saw him in person was, Who in the world had the idea of putting him at quarterback?

Not surprisingly, the number of hits a quarterback takes is a direct predictor of career longevity. Tom Brady doesn't take hits because his solution when a play breaks down is to chuck the ball into the turf. Brady has never been a runner, so it's almost always the right call. Newton's solution is either to stand in the pocket and wait -- often long enough to get sacked, or at least hit -- or take off and run. His physical attributes demand it -- why would a huge, fast guy like him throw the ball away when there are yards to gain? -- but both options result in him ending up on the ground.

Newton played as if he was indestructible up until the moment he self-destructed, and now every team with a need at quarterback is facing its own question: Will Newton's Third Law spawn Newton's Second Act?