The Chargers are casting a wide net for their search but would prefer to hire someone with prior NFL coaching experience, a source told Russini.
NFL clubs have reportedly been making calls to gather information on Harbaugh as a potential hire. He recently hired NFL agent Don Yee, who represents Tom Brady and Denver Broncos head coach Sean Payton.
Harbaugh can speak with teams before the conclusion of the divisional round. Since he's not an NFL coach, he can immediately begin interviewing with clubs following the National Championship.
The 60-year-old has been the head boss of the Wolverines since 2015. He was previously the coach of the San Francisco 49ers from 2011-14, helping lead the club to a Super Bowl appearance.
Harbaugh has brought consistent success to Michigan since taking over the job. The Wolverines are 39-3 over the last three seasons, making the College Playoff semifinal every year during that stretch.
The Chargers fired head coach Brandon Staley and general manager Tom Telesco following a 63-21 loss to the Las Vegas Raiders in Week 15. They're 5-11 heading into their season-finale against the Kansas City Chiefs.