Philbin was the Indianapolis Colts assistant head coach and offensive line coach the past two seasons, but he spent nine seasons with the Packers from 2003 through 2011, filling a variety of roles.
Pettine was a defensive coordinator with the New York Jets from 2009 to 2012, and was the coordinator for the Buffalo Bills in 2013.
Pettine was sacked in Cleveland in 2015, but consistently his more talented defenses in Buffalo and NY were among the league's best.
Mike Pettine, now 51 years old, wasn't employed by an National Football League team in 2017 but he did spend the season with the Seattle Seahawks studying their defense. Pettine has sat out the last two seasons, but apparently is ready to coach again in 2018.
The blitz-heavy 3-4 scheme Pettine employs is similar to Capers', which should give the Packers defense a slightly easier time adjusting to his system. He hired Joe Philbin, the former coach, to rejoin his staff likely as offensive coordinator to replace Edgar Bennett, who will not return. The Packers have finished outside the top 15 in the defensive rankings six of the past seven years.
The Packers also considered hiring in-house and had interviewed their remaining defensive assistants: Joe Whitt, Darren Perry and Winston Moss.