Sometime before kickoff Sunday, Ron Rivera and Leslie Frazier will sidle through their players warming up on the Metrodome turf to shake hands and perhaps even embrace in a bro hug worthy of their relationship as former teammates, colleagues and longtime friends.

Then the head coaches of the Carolina Panthers and Minnesota Vikings will retreat to their respective sidelines and get down to the task of ruining each other’s afternoon.

There can only be one happy ending on NFL game day.

Either Rivera or Frazier will emerge with his second victory of the 2013 season and more confident about an early-season turnaround. The other will plunge to 1-4, fanning the flames under an already hot seat.

Such are the stakes of the business they have chosen, which is what makes the second head-to-head matchup between these spiritual companions difficult.

“Very awkward,” Rivera said this week.

Frazier has home-field advantage and assistant coach Mike Singletary in his corner. Frazier, Rivera and Singletary were teammates on the 1985 Super Bowl champion Chicago Bears.

“Obviously I played with Mike, but I haven’t gotten a chance to coach with Mike,” Rivera said. “But they’re two really good men, and I do look forward to seeing them on Sunday.”

Frazier said he and Rivera talk at least once a week, although their regular pick-me-ups are on hold until Sunday’s resolution.

“He’ll share some things with how he’s doing things or how things are done where he is and whatever he thinks might be able to help me,” Frazier said. “So it’s mutual communication, where we’re both trying to encourage each other and help each other wherever we can.”

Before the season, Rivera called 11 current or former NFL coaches for advice about how he could improve, but Frazier is his closest confidant.

“Leslie’s probably one of the few people I can honestly say I do turn to for guidance in more ways than one, not just every day but in the spiritual sense,” Rivera said. “Leslie’s one of those really good people you can always rely on.”

In October 2011, Frazier bested Rivera, though just barely, when the Vikings defeated the Panthers 24-21 at Bank of America Stadium in Charlotte.

Carolina racked up 405 yards of offense that day and in the final minute, then-rookie quarterback Cam Newton drove the Panthers deep into Vikings territory only to have kicker Olindo Mare shank a 31-yard field-goal attempt that would have forced overtime.

It was one of only three victories for Frazier in his first full season as Minnesota’s head coach. Rivera, meanwhile, improved the Panthers by four wins over the 2-14 bottoming out that vaulted them to No. 1 in the 2011 draft, where they selected Newton — the Auburn sensation who became a Pro Bowl player as a rookie.

The Panthers finished 7-9 last season, winning five of their final six games.

A tough, 12-7 loss to Seattle in Week 1 was followed by a one-point loss at Buffalo. The Panthers rallied at home with a 38-0 blowout of the New York Giants in Week 3 before getting hammered 22-6 last week at Arizona.

Reports have surfaced suggesting Rivera, who is 14-22 in his first head coaching tenure, might be in jeopardy of losing his job if Carolina cannot reverse its fortunes. The Panthers have not made the playoffs since 2008, and Rivera’s teams are 2-14 in games decided by seven points or less.

Frazier’s status might not be as dire in Minnesota, where he is 17-25 with one playoff appearance. But he, too, is under pressure to overcome an 0-3 start and now finds himself the master of a three-ring quarterback circus.

“During this early stretch of the season we’ve tried to pick each other up at times,” Frazier said. “I just try to encourage him as best I can and share some insight from my perspective, and he does the same with me.”

Rivera became Carolina’s fourth head coach on Jan. 11, 2011, just the third Latino to lead an NFL team after Tom Flores with the Oakland/L.A. Raiders (1979-87) and Seattle Seahawks (1992-94) and Tom Fears with New Orleans (1967-70).

A second-round draft choice by Chicago in 1984, Rivera played linebacker nine seasons for the Bears, mostly behind Singletary.

“He had a chance to observe a lot, study a lot, always had the clipboard, taking notes,” Singletary said. “I told Ron when he was playing he would be coach.”

Rivera remained in the Chicago area after he retired but did not immediately transition into the profession until Frazier encouraged him.

Frazier was coaching defensive backs at the University of Illinois in the late 1990s when Rivera was hired by the Bears as a defensive quality control coach.

In 1999, Rivera joined Frazier on Andy Reid’s defensive staff at Philadelphia. They were together four seasons before Rivera became Lovie Smith’s defensive coordinator in Chicago and Frazier moved on to coach defensive backs under Tony Dungy at Indianapolis.

Their paths crossed again in Super Bowl XLI, where the Colts beat the Bears.

In 2007, Frazier was hired by Brad Childress to be the Vikings’ defensive coordinator, replacing him as head coach when Childress was fired with six games remaining in 2010. That same season Rivera was San Diego’s defensive coordinator and led the NFL’s No. 1-rated defense, becoming the hot coordinator candidate for a head coaching gig.

“Ron and Leslie are very similar,” Singletary said. “They’re both low-key guys that know what they want. Smart guys who know the game, know how to figure things out and had good experiences as teammates. They’re both the right men at the right times for their teams.”

Follow Brian Murphy at twitter.com/murphPPress. Murphy talks Vikings at 1:35 p.m. Mondays on WCCO-AM 830.