PHILADELPHIA -- The Buffalo Bills have contacted the Philadelphia Eagles about potentially interviewing offensive coordinator Frank Reich for their vacant head-coaching position, a league source told ESPN, confirming multiple reports. No official paperwork had been submitted as of Tuesday morning.

Reich has the sentimentality factor going for him in Buffalo. The backup to Hall of Famer Jim Kelly, he orchestrated one of the most legendary comebacks of all time, as the Bills rallied from a 35-3 deficit to upend the Oilers in a Jan. 3, 1993, wild-card game. The Bills interviewed Reich to be their head coach in 2015 before ultimately giving the job to the recently fired Rex Ryan.

Various reports have interim head coach Anthony Lynn as the front-runner for the job, though Bills general manager Doug Whaley emphasized that it would be an "open search" during his news conference Monday.

Frank Reich joined the Eagles this season as the team's offensive coordinator. He previously held the same position with the Chargers from 2014-15. Andy Lewis/Icon Sportswire

The Bills have also inquired about Carolina Panthers defensive coordinator Sean McDermott, who previously served as defensive coordinator in Philadelphia, according to reports.

Before joining the Eagles this past season, Reich was offensive coordinator for the San Diego Chargers from 2014 to '15. The Chargers ranked 18th and 26th in points per game in those two seasons. Head coach Doug Pederson currently calls the plays for the Eagles, who finished 22nd in total offense and 16th in points per game (22.9).

Reich is credited, along with Pederson and QB coach John DeFilippo, with helping to get Carson Wentz ready on very short notice this season.