Johnson, a 6-foot-2, 265-pound first-year player out of the University of Kentucky, entered the league as a non-drafted free agent with the N.Y. Giants in May 2010. He appeared in one game for the Miami Dolphins in 2010 and has spent time on the practice squads of Miami, Kansas City and Cincinnati. Johnson was most recently with the Bengals during the 2012 preseason. He earned first-team All-Southeastern Conference honors as a junior at Kentucky when he finished second in the conference with 93 tackles. Johnson will wear No. 94 for the Packers.