The Packers have an open session at Ray Nitschke Field this morning, as  organized team activities continue.  Defensive tackle Justin Harrell will miss the off-season practices for the second year in a row.  The Packers’ website says Harrell has a back injury.  He’ll be sidelined along with cornerback Will Blackmon,who has an injured foot, and defensive tackle Johnny Jolly, who has an injured shoulder.