This could be the training camp that determines whether the 2015 NFL MVP goes on to enjoy a Hall of Fame career, or leaves a legacy marked by inconsistency.
Coming off March surgery to repair a torn rotator cuff, Newton seems to know it.
The first pick of the 2011 draft, who has carried 260 pounds or more on his 6-foot-5 frame in past seasons, recently told the Panthers' website that he's the leanest he has been in any offseason. Recent pictures posted by Newton on social media -- with telling messages accompanying them -- seem to support that.
Newton has been great only once in his career -- the 2015 season, in which he led the Panthers to an NFL-best 15-1 regular-season record and the Super Bowl. He had a career-best 35 touchdown passes to go with 10 rushing scores in that campaign.
He has had other good years -- he was named NFL Offensive Player of the Year his rookie season, and posted a career-best 61.7 completion percentage and a 12-4 record in 2013 -- but none you could call great.
That he's coming off statistically the worst season of his career -- as well as shoulder surgery -- makes this camp pivotal. The Panthers' management spent the offseason surrounding him with playmakers such as running back Christian McCaffrey and slot receiver Curtis Samuel, giving Newton no excuse for failure.
Again, he seems to know this, telling the team website last month "my prime better be now."
All eyes will be on Newton, 28, when he makes his first throw of camp Wednesday night at Wofford College in Spartanburg, South Carolina.
He threw with many of his receivers for the first time since the surgery last week during his annual pre-camp gathering at the Under Armour facility in Baltimore. After Wednesday's news conference -- during which Marty Hurney was named interim general manager -- Coach Ron Rivera noted the shoulder is "apparently" fine.
But this will be the first time Newton has thrown with teammates in practice, in front of the public, since the final game of a disastrous 6-10 season.
Wednesday evening will mark the beginning of Newton's evolution from a dual-threat quarterback who relies on his legs to get him out of trouble into one who takes full advantage of other playmakers.
Once again, Newton seems to know it, telling the Panthers' website "my job is not necessarily to always be the playmaker."
The Panthers have leaned on Newton to be the team playmaker in past years. They have asked him to set up the running game with the read-option. He has been reluctant to take the check-down throws in favor of holding onto the ball and trying to throw the home run.
As a result, Newton has taken a beating.
He has taken far more hits than any quarterback since entering the league in 2011. He missed a game last season with a concussion. He became frustrated with questionable hits against him not resulting in flags, and he reached out to commissioner Roger Goodell to voice his concern.
He can't continue to take that kind of a pounding and be successful.
He knows it.
The Panthers know it.
Rivera said at the NFL owners meeting in March that his quarterback needed to "rebuild his confidence" -- a quality that also took a beating last season.
"He's human," Rivera said of his quarterback, who celebrates rushing touchdowns with a Superman move. "It was a tough year, but I also think it was a great learning experience for all of us, a humbling experience and something we can build on as we go forward."
For the Panthers to be successful moving forward, Newton's game must evolve. The defense, with the addition of defensive end Julius Peppers and a few other key pieces, should return to the top-10 form it displayed for four seasons prior to 2016.
The offensive line has been strengthened with the addition of free-agent left tackle Matt Kalil. Newton is surrounded by more dynamic playmakers than he has had at any point in his career.
He has to take advantage of them.
It begins in training camp. This is where Newton's career could be defined. And he seems to know it.