Schwartz was the first assistant brought in by new head coach Doug Pederson. He last coached in 2014 as Buffalo's defensive coordinator.
Schwartz was 29-51 as Detroit's coach from 2009-13. He led the Bills to the No. 4 ranking on defense in 2014. Schwartz was Tennessee's defensive coordinator for eight seasons before going to Detroit.
Pederson announced the hiring at his introductory news conference on Tuesday. Pederson also said he would retain from Chip Kelly's staff offensive line coach Jeff Stoutland and special teams coach Dave Fipp. Running backs coach Duce Staley also is expected to remain.
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