Also on Monday, the club waived running back Brandon Minor from injured reserve.
Johnson (6-foot-1, 263 pounds) is a third-year player who played 24 games (5 starts) for Tennessee (2011) and Green Bay (2009-10), totaling eight receptions for 60 yards (7.5 avg.). He also started two-of-three postseason games played for the Packers during the 2010 season, recording one reception for four yards.
He was selected by Green Bay in the fifth round (145th overall) of the 2009 NFL Draft from Louisiana State University, where he played 40 games (15 starts) for the Tigers and totaled five rushing touchdowns in 16 career carries.
A fullback and linebacker at West St. John High School in Edgard, La., Johnson was born on Sept. 30, 1986, in New Orleans.