According to Geoff Mosher of CSNPhilly.com, tight end Clay Harbor worked at linebacker and wide receiver Jason Avant played some cornerback.
Just talked to Clay Harbor & Jason Avant. Harbor spent 1 day practicing at OLB. Avant has seen time at DB.
— Geoff Mosher (@GeoffMosherCSN) May 18, 2013
It looks like Kelly is getting in touch with his inner Bill Belichick.