On the day of the last Denver Broncos game of the 2016 season, rumors are swirling of coach Gary Kubiak’s retirement, along with speculation that Atlanta Falcons offensive coordinator Kyle Shanahan may be a leading replacement candidate. Shanahan is the son of former long-time Broncos coach Mike Shanahan, who headed the club’s helm to win two Super Bowls. Kubiak is the only other Broncos head coach to have won an NFL championship.

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Shanahan, 37, has been an NFL offensive coordinator for four teams.

Houston Texans (2008–2009)

Washington Redskins (2010–2013)

Cleveland Browns (2014)

Atlanta Falcons (2015–present)

He became the youngest NFL coordinator when hired by the Texans. Lasting less than a year with the Browns, Shanahan resigned as a result of his objection to the Browns front office’s decision that rookie quarterback Johnny Manziel should start. Shanahan has previously served in positions an assistant coach for quarterbacks and for wide receivers.

The Broncos have suffered from from a poorly performing offense for much of the season. Through Week 16 of the season, the club ranks No. 27 in total offense with 4,820 yards. In contrast the Falcons have the second-highest total with 6,188 yards, with a balance attack of 4,402 passing yards and 1,786 rushing yards. Those ranks No. 3 and No. 6, respectively.

Falcons Matt Ryan has the highest quarterback rating of 115.5 in the NFL, throwing an average of 308 yards per game. Broncos starting quarterback Trevor Siemian is ranked No. 24 with a rating of 83.9, at 239 yards per game. With the firing of Buffalo Bills coach Rex Ryan, there is the possibility that quarterback Tyrod Taylor may become available to the Broncos.

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Kubiak, 55, is expected to retire primarily due to health concerns. He was hospitalized after a Broncos’ 23-16 loss to the Falcons in Denver on Oct. 9. Diagnosed with a complex migraine, Kubiak sat out the following game against the San Diego Chargers. Before the the Falcons game, the Broncos had a 4-0 records. Afterward the club has gone 4-7. For the first time since John Elway took over football operations in 2011, the Broncos will miss the playoffs this season.