The Packers opened up a roster spot Tuesday but releasing veteran defensive end Michael Montgomery.  He was brought back to the team on October 15 but barely saw the field.   His release opens a roster spot presumably for one of the players coming off the Physically Unable to Perform list to be activated, either Al Harris or Atari Bigby. Wide receiver Donald Driver told a Milwaukee media outlet yesterday his quadricep injury will keep him out of the Dallas game Sunday night.  Driver has been hampered by both a quad bruise and a strain over the past couple of weeks.  He failed to catch a pass in either game, after recording at least one reception in a club record 139 games including the playoffs.  Defensive back Pat Lee is likely to miss the Cowboys game as well with an ankle injury.  The team returns to the practice field today.