Reich spent the past two seasons calling plays for the Chargers before the team fired him earlier this month on the heels of San Diego's 4-12 implosion.
The Chargers had plenty of problems, but wound up as the ninth-ranked offense and the NFL's fourth-best passing attack last season. They piled up yardage, but San Diego also finished last in rushing and a dismal 26th in scoring.
Rookie running back Melvin Gordon struggled under Reich's direction, but Reich can also be seen as a convenient fall guy for coach Mike McCoy and general manager Tom Telesco, who were retained despite the wreckage.
In Philly, Reich -- the former Bills quarterback -- will take over the remains of a Chip Kelly-built roster with more questions than answers heading into 2016. Will Sam Bradford be re-signed? Can DeMarco Murray regain his 2014 form alongside fellow running back Ryan Mathews? Will a playmaking receiver emerge?
Pederson will have the final say in all of that and might choose to call his own plays, too. In Reich, though, the Eagles have an experienced assistant willing to put the memory of Kelly in the rear-view mirror. For now, that's enough.