Six candidates have emerged in the Denver Broncos head coach search after the abrupt and shocking firing of John Fox. After posting a 46-18 record with a four division titles and a trip to the Super Bowl over four seasons, Fox was let go by the Broncos on Monday, a day removed from the team’s 24-13 AFC Divisional round loss to Indianapolis.

According to The Denver Post, Broncos team president John Elway has targeted Seattle Seahawks defensive coordinator Dan Quinn, Detroit Lions defensive coordinator Teryl Austin, and Baltimore Ravens offensive coordinator Gary Kubiak, and quarterbacks coach Rick Dennison.

There is also the possibility of Denver promoting current offensive coordinator Adam Gase or defensive coordinator Jack Del Rio, but the latter is reportedly the first choice of the San Francisco 49ers and the former is evidently close to signing on the with the Oakland Raiders.

The 49ers reportedly met with Gase in Denver Tuesday, and the 36-year-old sat down with Elway on Wednesday morning, but it’s unknown if the two discussed the Broncos job. Perhaps hoping to avoid losing all three of their top coaches in a three-day span, it’s possible the Broncos will try to entice Gase to stay with a major offer.

But whoever takes over for Fox, or even interviews with the Broncos, will likely have several questions for their possible future employer, with the first being the future of five-time MVP quarterback Peyton Manning.

Though he’s signed through 2016, Manning’s future in the NFL is unclear. He could retire, but would away from $43 million in salary, not to mention ending his storied career with one of his worst postseason performances.

Injury could also be a major concern for Manning, and they have derailed his career before. After the loss to Indy, it was revealed that Manning suffered a torn quadriceps muscle and played through the injury in the last month of the regular season and into the postseason. The 38-year-old was forced to sit out the entire 2011 season after undergoing several surgeries on his injured neck, and his career was in the balance.

But assuming Manning is both healthy and ready to make another run to the postseason, the Broncos front office has to ink fresh contracts with his two top targets. Receiver Demaryius Thomas, who led Denver with 111 receptions for 1,619 yards and 11 touchdowns, and tight end Julius Thomas will both be unrestricted free agents in the offseason. The former Thomas led the team with 12 touchdown receptions.

It remains to be seen what the Broncos would offer either of the unrelated Thomas’s, but they might have to make several moves to fit everyone under the salary cap; especially if Demaryius Thomas demands a contract as rich as the one Detroit gave their top receiver, Calvin Johnson. Denver currently has $116.1 million devoted to player salaries next season, according to figures compiled by Spotrac, which would put them under next year’s projected cap, but again it depends on what both players demand.

Quinn could very well be atop the Broncos list, but he’s got the Seahawks poised for a second-straight Super Bowl run and can’t be officially hired until they win it all or get eliminated.

Austin’s another coveted candidate after his incredible work in only one season in Detroit, helping the Lions make the postseason with the league’s No. 2 defense.

Kubiak and Dennison could be potential frontrunners. Both exclusively donned Broncos uniforms in their playing days in the late 1980s and 1990s, and Kubiak has the most head coaching experience of anyone under consideration. Kubiak manned the Houston Texans for eight seasons, racking up a 61-64 record and two AFC South titles, but was let go after a 2-11 season last year.

However, many reports have said Kubiak is not interested in leaving Baltimore.

Dennison evidently finished second to Fox in the Broncos search back in 2011, The Post reported, so he’s certainly been a highly attractive candidate to Elway before. He moved into coaching in 1995 as an offensive assistant for the Broncos, and over 13 years worked with many facets of the offense and special teams before joining Kubiak for his last three years in Houston and now in Baltimore.

There is of course former Denver head coach Mike Shanahan. He’s met with many teams in the offseason, like Chicago and San Francisco, but so far there have been no takers.

No reports have linked him to the Broncos job, but Shanahan and Elway of course won back-to-back Super Bowls in 1997 and 1998. Still, his poor four-year stint with Washington might have tainted Shanahan’s future prospects.