Nick Barnett's season is officially over.  After undergoing wrist surgery earlier this week, the Packers have placed their middle linebacker on injured reserve.  Barnett was just 8 tackles away from supplanting John Anderson as the all time franchise leader in tackles.  He was injured against the Detroit Lions two weeks ago.  To take his roster spot, the Packers have re-signed defensive end Michael Montgomery.  He was drafted by the Packers in the 6th round of the 2005 draft out of Texas A&M.  He played in 56 games with five starts with Green Bay before the Packers allowed his contract to expire after last season.  He signed a free agent deal with the Minnesota Vikings but was released at the end of training camp.  The Packers are dangerously thin at defensive end heading into this week's Miami game.  Ryan Pickett has a bad ankle and will likely miss the game, rookie Mike Neal has a shoulder injury and may not play, leaving the Packers with Cullen Jenkins, still playing with a broken hand, nose tackle BJ Raji and rookie CJ Wilson as the only healthy defensive lineman.