The interview reportedly took place in Jacksonville on Monday, with the Chargers in town to take on the Jaguars.
The Chargers have not confirmed if the interview took place, or if Reich needed or was granted permission to interview for the head coaching vacancy.
Reich played quarterback for the Terrapins in college, where he engineered the greatest comeback win in college football history. During his senior season in 1984, Reich brought Maryland back from a 31-0 deficit for a 42-40 win over the University of Miami.
Reich was a candidate for head coaching jobs with the Buffalo Bills and New York Jets last year. He commands a room, carries himself like a head coach and has a good reputation around the league in the NFL.
Under Reich's guidance, the Chargers are No. 6 in the league in total offense, averaging 391 yards a contest. However, the Chargers have struggled to score points (22.2 points per game, No. 19 in NFL) and run the football this season (82 yards per contest, No. 30 in NFL).
And with Mike McCoy's head coaching tenure on shaky footing in San Diego with his team losing 11 of its past 15 games dating back to last season, Reich appears to be exploring his options elsewhere.
Reich, who turns 54 on Friday, has never been a head coach in college or in the pros.