This season, defenses are demonstrating a couple of simple ways to push Newton to his breaking point.
The Seattle Seahawks defense became the fourth to nullify Newton this with a simple serum of discipline, hard hits and frustration, but are the first to come out and disclose not just a hope to hold him in check, but to push him to the brink of quitting as part of the program.
"We know he's a great dual-threat quarterback, but once we bottle it up and frustrate him, we know he's going to tank a bit," said safety Earl Thomas after the Seattle Seahawks kept Newton's Panthers out of the end zone offensively in a 16-12 victory on Sunday. "We were able to do that."
Newton, the NFL Rookie of the Year last season, caused fits for defensive coordinators with the dual threat of passing and running, coupled with a capable running game, featuring DeAngelo Williams and Jonathan Stewart. Defenses last season spoke haltingly of success against him and glowingly of the tools he brought to the matchup.
But in Carolina's 1-4 start to 2012, the trend disturbing to Panthers fans began when Tampa Bay implored its defense to "wrap and roll" the mobile quarterback, resulting in a career-low in rushing yards (four) and a 16-10 Bucs victory.
Tampa Bay sacked Newton three times for 12 yards in losses, exactly two yards more than Newton, Williams, Stewart, Mike Tolbert and Kealoha Pilares amassed together on the ground.
"He gets himself going by running the ball," Bucs linebacker Mason Foster told Yahoo Sports after that opening-day victory. "It was frustrating to him."
In fact, the only defense that hasn't frustrated Newton this season has been New Orleans', which currently ranks last in yards surrendered (456), 29th in passing yards given up per game (283.2) and 30th out of 32 teams in points per game (30.8).
The New York Giants dismantled Newton's offense in prime-time on a Thursday night in Week 3, holding the quarterback to six rushing yards and 125 first-half offensive yards and kept Carolina's offense out of the end zone until the third quarter, with the outcome already decided.
"We got some licks on him, when he kept the ball," Giants coach Tom Coughlin said of the night.
"Who wants to support something that puts on a performance of embarrassment out there?" Newton asked after that 36-7 drubbing.
The long week to follow was punctuated by the buzz surrounding teammate Steve Smith blasting Newton for his hammer-time demeanor when he sulked on the sideline after backup Derek Anderson took his place on the field.
With extra time to prepare for the Atlanta Falcons the following week, Newton's offense showed glimmers in a 30-28 road loss. Newton tossed two touchdown passes and ran for another, but fumbled after appearing to gain enough yardage on a late 3rd-and-2 while protecting a lead, giving Atlanta a chance to win with a field goal.
"There are a lot of guys that are trusting the ball carrier, and I was the ball carrier on that particular play to get the job done," Newton told the Associated Press afterward. "And I dropped the ball."
Seattle's league-best defense (258.6 yards per game) probably wasn't the break Newton needed next.
In a 16-12 loss in which Carolina's only touchdown came on defensive back Captain Munnerlyn's interception return, Newton wound up with career-lows in completion percentage (41.4) and passing yards (141).
Still, as was the case against Atlanta, Newton had the Panthers' fortunes in his hands in the end.
Despite going 5-for-20 passing in the first three quarters against Seattle, Newton led the Panthers on a potential winning drive, but on 4th-and-goal, his pass to wide-open Ben Hartsock bounced harmlessly on the turf in the end zone.
"Call it what you want to call it," Newton said. "Cam Newton didn't play good football today. You can hint around whoever, you can say the pass rush, whatever."
The hints—and stats—are adding up. Four losses. Five interceptions against 17 last season. Newton has already matched 2011's total of five fumbles, two lost.
With a bye week, then a home game against Dallas before traveling to Chicago and Washington, Panthers fans will continue to look for Newton's signature game-changing play, Carolina's run game to return and its young quarterback, who has yet to register a signature comeback win, to hold a late lead, or lead a rally to restore the confidence.
"He was maybe a little anxious, maybe he was pressing again," Panthers coach Ron Rivera said of Newton in the loss to Seattle. "He is a young quarterback who is learning and growing. He is getting better. We are going to stick with him obviously, because he's our guy of the future."
Eli Pacheco is a Contributor for Bleacher Report. Unless otherwise noted, all quotes were obtained firsthand.