He's set to replace Darrell Bevell, who's expected to join the Jacksonville Jaguars. Lynn will reportedly join a revamped coaching staff that includes head coach Dan Campbell and defensive coordinator Aaron Glenn.
He's spent much of his career as a running backs coach, occupying that role with numerous teams from 2003-16. His work earned him a promotion in 2017 to head coach of the Chargers, where he put together a 33-31 overall record. He was fired following the conclusion of the 2020 season after two straight losing campaigns.
The Chargers' offense held its own under Lynn, never finishing lower than 11th in yards per game and ranking as high as fourth in 2017.
Lynn is set to work with a Lions offense that finished 20th in yardage and scoring last season. Detroit will also likely have a new quarterback under center after reportedly agreeing to explore trades for Matthew Stafford.