Nate Davis

USATODAY

With 20 of the NFL's 32 teams sitting at .500 or better after Week 13, most coaches and players in the league are hoping a December hot streak will carry them into the playoffs.

But elsewhere, heat of another kind is starting to build. Regime change is a constant in the ever-evolving NFL, and several coaches are bound to be looking for work by the end of the month.

HOT SEATS

1. Tony Sparano, Raiders: In reality, this was always an ejection seat, and Sparano knew it when he took the interim coaching reins from deposed Dennis Allen after Oakland's 0-4 start. Prior to Sunday's 52-0 debacle in St. Louis, Sparano had made Oakland generally competitive and helped spare them from 0-16 ignominy. But a major housecleaning is virtually inevitable for an organization that's had double-digit losses in 10 of the past 12 seasons.

2. Rex Ryan, Jets: He nearly took the Jets to the Super Bowl twice. But since that second consecutive AFC Championship loss at the end of the 2010 campaign, Ryan's Jets are 24-36 (.400). He saved his job with a fast finish in 2013, but that seems unlikely to happen again, especially given the lack of talent on the roster (which is why GM John Idzik may also be in the crosshairs). But a dejected Ryan sure seemed like a dead man walking after Monday night's gut-wrenching come-from-ahead loss to the Dolphins, disbelieving himself that his team could actually be 2-10.

3. Tom Coughlin, Giants: He's enjoyed a long leash and deservedly so aftefr bringing home two Super Bowl wins. But it's been feast or famine in Coughlin's tenure. Outside of those title runs, he doesn't own a playoff victory during any of his other nine seasons in New York. And the Giants are 19-25 without a playoff appearance since they won Super Bowl XLVI following the 2011 season. Worse, they've currently lost seven in a row and surrendered a 21-0 lead to the lowly Jaguars on Sunday. The Mara family has long made the Giants one of the NFL's most stable operations. But in a "What have you done for me lately?" league, Coughlin may leave co-owners John Mara and Steve Tisch little choice.

4. Marc Trestman, Bears: Where did it all go wrong? His high-tech offense infused excitement into this stodgy franchise a year ago, and only a blown coverage in a Week 17 loss to the Packers prevented them from winning the NFC North. Now? QB Jay Cutler has regressed into many of his bad habits, and the offense's production has been way off its 2013 pace. Defensively, the Bears are in the midst of arguably their worst two-year stretch in the organization's 95-year history. This franchise has long been known for toughness and grit. Right now, it's enigmatic and seemingly full of players not afraid to express their displeasure, not good signs for Trestman.

5. Mike Smith, Falcons: The most successful coach in franchise history may ultimately benefit from competing in what appears to be the worst division in NFL history, the 2014 edition of the NFC South. Though only 5-7, Smith's team has overcome a five-game losing streak to win three of four and earn a tenuous first-place perch. Still, Smith's infamous game management blunders have resurfaced this season and may have cost the Falcons a valuable Week 12 victory over the Browns. And the patience of owner Arthur Blank, who bemoaned the Falcons' toughness in the offseason, has appeared to grow increasingly thin in recent years with this talent-laden squad unable to get over the Super Bowl hump since Smith and GM Thomas Dimitroff took charge in 2008.

HEATABLE SEATS

Gus Bradley, Jaguars: He's overseen what's almost inarguably the least talented, least experienced roster over the past two seasons. Bradley's competitive spirit, patience and wellspring of optimism have largely been ideal to the Jags' rebuild. Not many coaches survive a 6-22 stretch where their team is blown out more often than not. But with so many first- and second-year starters, Bradley seems more likely to get the chance to reap what he's sewn in 2015.

Jason Garrett, Cowboys: Dallas has had a feel-good season with Garrett rewarding owner Jerry Jones' patience after three consecutive 8-8 finishes. Yet the Cowboys have dropped three of five since their 6-1 start and currently reside outside the NFC playoff field. And Garrett's clubs don't have a history of finishing well, going 8-11 in December since his battlefield promotion over Wade Phillips in 2010. Would another collapse cause the ouster Garrett has dodged to this point?

Marvin Lewis, Bengals: He's on the cusp of taking Cincinnati to the playoffs for the fourth straight year, unprecedented success for this team. Mike Brown is also one of the more loyal owners in the league. Still, Lewis has been on the job for 12 seasons and has yet to deliver a postseason win, perhaps the reason why Brown only extended his deal through the 2015 season in March.

Doug Marrone, Bills: Buffalo is 7-5 and could finish with its first winning record since 2004 and possibly break a 15-year playoff drought, the NFL's longest current absence. The major factor working against Marrone, who's only in his second year on the job, is a change in ownership, which so often signals a lot of turnover at the top. However Terry Pegula didn't immediately clean house when he bought the NHL's Sabres, perhaps a good sign for Marrone and GM Doug Whaley.

Joe Philbin, Dolphins: His resume shows a 22-22 record in two-plus seasons and is marred by one major scandal and zero playoff trips. However Miami has won five of seven and currently holds the AFC's second wild-card berth. Changing the locker room culture and punching the organization's first playoff trip since 2008 would surely save Philbin. Otherwise, who knows?

ADJUSTABLE SEAT WARMER

Jim Harbaugh, 49ers: A 48-19-1 record (including playoffs) with one Super Bowl trip and three NFC Championship Game showings since he was hired in 2011 would suggest Harbaugh should be firmly entrenched with the ability to control the Nordic package heating under his driver's seat. But he evidently likes his khakis warm. Harbaugh and owner Jed York have not agreed to a contract extension even with the deal set to expire following the 2015 season (few coaches work under lame duck status). And amid the team's current struggles, including an embarrassing Thanksgiving loss to the archrival Seahawks that had York apologizing to the fan base, reports that Harbaugh could be traded or is seeking an escape hatch have resurfaced.