Even though the NFL preseason has just begun, there are already head coaches that will need their teams to have strong, winning seasons in 2017 in order to keep their jobs for another year. Typically, six to eight head coaches lose their jobs after (or sometimes during) a given season, and there are five at present whose seats are already hot before a single game has been played.

So, who are these men and what will it take -- beyond winning -- for them to remain employed by their current teams beyond the 2017 season?

Ron Rivera, Carolina Panthers

Three of Ron Rivera's six seasons as the Panthers head coach has led to first-place finishes in the NFC South, most recently in 2015, when the Panthers boasted a 15-1 regular-season record and went all the way to the Super Bowl. But in the what-have-you-done-for-me-lately league, the Panthers' 6-10 fourth-place divisional finish a season ago does Rivera no favors.

Nor does the firing this week of general manager David Gettleman. Gettleman, hired in 2013 to replace former general manager Marty Hurney, has now been replaced by the returning Hurney on an interim basis. Rivera told the Charlotte Observer's Scott Fowler on Tuesday that he was not consulted by team owner Jerry Richardson about the move to fire Gettleman, and though he also believes that he's not the next to go, what happens over the next six months will certainly determine just now much job security Rivera really has.

The first step will be getting a healthy Cam Newton back on the field. Newton, who underwent offseason surgery to repair a partially-torn rotator cuff, did not throw during the team's OTA and minicamp practices, though is expected at some point to be a full participant in training camp. But winning relies more than just on the health of the quarterback, though that's clearly where it begins.

The offensive line tasked with protecting Newton -- and creating running lanes for him, rookie running back (and receiving threat) Christian McCaffrey -- is still a work in progress, with three starters landing on injured reserve a year ago and one, right tackle Michael Oher, remains in the concussion protocol and may not even be on the roster to close the summer. The team also hasn't found an adequate replacement for cornerback Josh Norman, whom the team released a year ago.

The complexion of the NFC South has changed dramatically since the Panthers spent three seasons dominating it. The Falcons are coming off of a Super Bowl of their own and the Tampa Bay Buccaneers continue to trend upward thanks to the way they have managed their roster. Another losing season capped off by the hiring of a new, permanent general manager could send Rivera packing in January.

Chuck Pagano, Indianapolis Colts

It's been surprising just how much time Colts owner Jim Irsay has afforded head coach Pagano. It seemed that Pagano was destined to lose his job, along with then-general manager Ryan Grigson, following the team's 8-8 finish in 2015. Instead, Irsay allowed Pagano and Grigson one year to work out their differences and turn the team's fortunes around. And after another 8-8 finish in 2016, the only change that came was Irsay relieving Grigson of his duties; Pagano remains the head coach for at least the 2017, while Chris Ballard serves as the general manager.

The main strike against the Pagano era (and speaks just as much to the failings of Grigson) is the inability to build a strong supporting cast around quarterback Andrew Luck. Beyond just stocking his shelves with numerous skill-position weapons to make his life easier, the protection (poorly) afforded him by Pro Football Focus' 25th-ranked offensive line in 2016 led to the $123-million man missing nine games in 2015 with shoulder and abdominal injuries and to playing through all of last season with the same shoulder injury, which has since required offseason surgery.

That surgery, which took place in January, takes around six or as many as nine months to heal completely, which means Luck has yet to start throwing footballs and puts his status for the start of training camp in doubt, not to mention his availability for Week 1's contest against the Los Angeles Rams. With the Colts trying to overcome three straight years of slow starts (they have been 0-2 to open the season over the last three years), Luck missing any time would not help those efforts.

It is, though, how the Colts finish and not how they start that will dictate Pagano's future in Indianapolis. Being a part of the unpredictable AFC South could work out in the Colts' favor. Further, if Luck has to miss any time to open the year, that may also help Pagano's cause -- after all, who can blame a coach for losing if the star quarterback isn't available to throw the passes? But Pagano is running out of excuses, especially with Grigson gone. This also means he is running out of time. The Colts need to do better than .500 in 2017 if Pagano is going to have any job security.

Sean McVay, Los Angeles Rams

In the five years that Jeff Fisher was the head coach of the Rams, he never had a winning season; 7-9 was the best he could do. Fisher lost his job before the 2016 season even ended, and when the Rams finally found his replacement they decided to go younger -- way younger. McVay, now 31 years old, is the youngest head coach in the NFL.

McVay, who was the Washington offensive coordinator from 2014 through 2016, is now tasked with turning around a run game led by Todd Gurley that stalled out a season after Gurley earned Offensive Rookie of the Year honors. He also inherits quarterback Jared Goff, the first-overall pick in the 2016 draft and whose seven starts a year ago were all losses; he also threw five touchdowns to seven interceptions while being sacked 26 times.

For what its worth, Gurley is excited about the offense McVay has been crafting this year, finding it more "Todd friendly," and also noting that Goff's offseason has been "great." But words are one thing and actions are another. If McVay cannot get Gurley running effectively nor pull appreciable development out of his young quarterback, his tenure as Rams head coach could be of the one-and-done sort. The Rams need something to provide a spark, especially to its Los Angeles fan base one year after relocating. General manager Les Snead says there is "authentic chemistry" to his relationship with McVay, but another string of losses -- the Rams won only one game between Weeks 5 and 17 last season -- would certainly start wearing away at it, and at his patience.

Marvin Lewis, Cincinnati Bengals

In the past 14 seasons Lewis has been the head coach of the Bengals, his team has made the playoffs seven times, including every year from 2011 through 2015. But his team has usually fallen early in the postseason, and in 2016 dropped to a disappointing 6-9-1 finish, good for third in the AFC North. Lewis is also on a one-year coaching contract that makes him in danger of finally losing his job following the 2017 season if there are few improvements to his team's win-loss record.

That said, Bengals owner Mike Brown has an unwavering loyalty to Lewis. And despite all of Lewis' teams' struggles in the postseason, his 118 wins and seven years at .500 or better help his job security, even if it's a matter of him being given yet another one-year extension.

But it should be noted that the Bengals may seriously struggle on offense again this year, particularly on the line where they lost tackle Andrew Whitworth as well as guard Kevin Zeitler. Though the additions of explosive skill position players John Ross and Joe Mixon via the draft could help the Bengals this year, without a reliable line both the run game and the ability of quarterback Andy Dalton to stay upright long enough to complete a pass are jeopardized.

Precedent says that no matter what the Bengals' 2017 win-loss record looks like, Lewis won't lose his job. But given that he's on a one-year deal and the on-field product could continue to trend downward, it's hard to keep Lewis completely off of the hot seat heading into the season.

Todd Bowles, New York Jets

The Jets as a whole appeared to give up on their way to a 5-11 finish a season ago, and this year doesn't look to be much brighter. The team doesn't have any truly viable option at quarterback from a long-term standpoint, with Josh McCown presently holding the edge over Bryce Petty and Christian Hackenberg. Their top receivers in recent seasons, Brandon Marshall and Eric Decker, are both gone, leaving Quincy Enunwa as the unit's elder statesman. And even he believes that the Jets -- or at least the front-office staff and other powers-that-be -- are choosing tanking as an option for the team's 2017 campaign.

None of this is good news for Bowles as he heads into his third season helming the Jets. While "tanking" is often a convenient word to describe the more complicated "rebuilding," another bad year of five wins or less will require someone to shoulder the blame. And that person may just end up being Bowles, even if it would be more appropriate for general manager Mike Maccagnan to take that particular bullet.

There is more at play with the Jets than just the lack of winning and the jettisoning of talent along the roster. There is also the poor morale factor that may not be able to be eradicated until Bowles' and Maccagnan's eras come to an end. Unless the Jets have a surprisingly successful year, there is no coaching seat hotter than Bowles prior to the start of the season.