Wells also hurt his knee Sunday and had to sit out when the team practiced Tuesday.
"I had a lot of swelling in it Monday and Tuesday, so basically we waited on the swelling to go down so I could bend it again," Wells said. "Nothing's torn. The MRI was clear. It's just a whole bunch of fluid in there."
With Spitz out for the season because of a lower back injury, there isn't much experience behind Wells. His backup is Evan Dietrich-Smith, an undrafted free agent rookie from Idaho State.
Backup running back Ahman Green continued to sit out practice with a groin injury and is doubtful for Thursday's game.
Also, the Packers placed Harris on injured reserve and signed cornerback Trevor Ford from the practice squad Wednesday.
Copyright 2009 by The Associated Press