The Denver Broncos are expected to extend an offer to Miami Dolphins defensive coordinator Vance Joseph to be their next head coach, sources told Troy Renck of 9News.

Joseph was set to travel Wednesday to interview with the San Diego Chargers, but instead, he returned to the Broncos' facility, reports NFL Network's Ian Rapoport, citing sources.

The 44-year-old met with the Broncos' hierarchy for four hours Tuesday and made a strong impression on the team, reports Renck.

Joseph has been the front-runner for the position since the process began, with Atlanta Falcons offensive coordinator Kyle Shanahan believed to be the other leading candidate.

The potential hiring of Joseph makes the future of defensive coordinator Wade Phillips - whose contract expired at the end of this season - even more uncertain.

The Dolphins' defense was the 29th-ranked unit in the league under Joseph, but Broncos general manager John Elway praised his "great leadership qualities and a strong vision of what it takes to win" after their interview Tuesday.