CHARLOTTE, N.C. -- It's not just time to sit Cam Newton for the rest of the season. It's time for the Carolina Panthers to consider a potential long-term replacement for their franchise quarterback in free agency or the NFL draft.

The uncertainty surrounding lingering problems with Newton's right shoulder raises many questions that extend beyond Carolina's six-game losing streak and 1 percent chance of making the playoffs. If the 2015 NFL MVP needs to have a second shoulder surgery in less than two years, what are the long-term implications? Would he miss an entire season, as Indianapolis Colts quarterback Andrew Luck did in 2017 after having a similar surgery?

And if surgery isn't the answer, would resting Newton for the next two games and the entire offseason assure this issue won't reappear in 2019?

Remember, Newton said prior to this season that he felt better than he had in years. Then, after he threw 22 passes in the fourth quarter of a come-from-behind win in Philadelphia in Week 6, the Panthers began limiting his throwing in practice to, for the most part, one day a week.

Cam Newton, who has a sore right shoulder, struggled throwing the ball more than 10 yards down the field in a 12-9 loss to New Orleans on Monday. Streeter Lecka/Getty Images

Newton played well the next two weeks to help Carolina improve to 6-2. Even after the team fell to 6-5, the 2010 Heisman Trophy winner boasted he was playing the best football of his career. Then he threw four interceptions the next game in Tampa Bay.

Newton has now thrown at least one interception in six straight games after throwing one in only three of the first eight.

Newton's arm strength has been such an issue that backup quarterback Taylor Heinicke has come in for a Hail Mary pass three times.

The frustration never was more magnified than after Monday night's 12-9 loss to the New Orleans Saints, in which Newton came up short on short passes. The 29-year-old quarterback was almost begging for answers as to why he continues to have soreness and stiffness in the shoulder, for why everything from acupuncture to massages hasn't helped.

He had none.

"You can't rub magic dust on it, go to this or that person, have the placebo things done where you think certain things are what they are -- and you come out and you're still the same," Newton said. "Over the past couple of weeks, nothing has really changed."

One thing has. The Panthers (6-8) are for all practical purposes out of the playoff picture, and they're focused on next season with two games remaining against Atlanta and New Orleans.

That puts the onus on coach Ron Rivera and the medical staff. As of Tuesday, Rivera wasn't willing to commit to sitting Newton the final two games because the Panthers have a "slim glimmer" of hope of making the playoffs.

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That "slim glimmer," according to ESPN Stats & Information, is less than 1 percent.

"I can't tell you what I'm going to say until I get an opportunity to know where he is in terms of his physical state and mental state," Rivera said Tuesday of his plan for Newton. "It's a tough situation right now. Until I get a chance to visit with him, I'm not going to speculate."

It's a tough situation in many ways. Newton wants to play and there has been no indication that playing would make the shoulder worse. Rivera wants to win, and the next two games could play a role in whether owner David Tepper keeps the head coach on staff for a ninth season. An eight-game losing streak after a 6-2 start wouldn't be good for Rivera's résumé. Since the NFL transitioned to a 16-game schedule in 1978, no team has gone from 6-2 to 6-10.

Rivera didn't exactly sound like a coach who has been given a vote of confidence on Tuesday.

"Absolutely, because I don't know," Rivera said when asked how much he hates being asked about his future. "I've been through it a couple of times my first two seasons [6-10, 7-9]. But at the end of the day, it comes down to one person, and that's the only one that knows."

If Rivera returns, he'll need a healthy Newton to succeed. If Newton isn't healthy, Rivera will need a healthy option.

The team could find its next quarterback through free agency. Philadelphia's Nick Foles and New Orleans' Teddy Bridgewater are options the Panthers could target if they want a quarterback who can win immediately. Whether either would want to join a situation where they potentially could remain a backup is a big question.

The draft is also an option. The Panthers haven't drafted another quarterback since making Newton the No. 1 pick in 2011. Scouts don't consider the incoming quarterback class particularly strong, so Carolina would likely pursue a project in the middle rounds.

The Panthers have been looking for a potential long-term replacement for Newton outside of the draft since Marty Hurney returned as the general manager before the 2017 season.

They've brought in several candidates in free agency (like Garrett Gilbert and Joe Webb) who haven't panned out. They moved on from veteran Derek Anderson as Newton's backup this season and went with Heinicke because of his previous experience in offensive coordinator Norv Turner's system at Minnesota.

But the Panthers don't really know what they have in Heinicke, who hasn't started an NFL game and has thrown only five passes in two seasons. The next two games offer an opportunity to see if Heinicke can be a legitimate starter who can win games. If he can't, that makes the team's offseason quarterback decision even more critical.

At this point, Rivera isn't ready to commit to playing Heinicke until somebody from the medical staff says he needs to shut Newton down. He didn't sound like a coach ready to give Newton a clipboard on Tuesday.

"We'll get an opportunity to visit and talk," he said of meeting with Newton and his medical team later in the day. "I'll get a chance to see where he is mentally. Hopefully, he'll be able to get past this one and we'll go from there."