Ferguson's injury, coupled with the losses of Pro Bowl receiver Javon Walker and rookie Terrence Murphy earlier this season, leaves the Packers very thin at the position. Donald Driver is the team's top receiver and currently is backed up by Antonio Chatman and Jamal Jones.
Ferguson had two catches for 52 yards against the Vikings Sunday. He is third on the team with 17 catches for 279 yards and three touchdowns this season.
"We still got 10 games left," said Driver, who led the Packers Sunday with eight catches for 114 yards and a touchdown. "The last 10 games will be hard, but we'll do what we can do to get one win."
Jones hurts shoulder
Besides losing Ferguson for up to a month, Jamal Jones suffered a shoulder contusion.
It's not known whether Jones will have to miss any practice time later this week as the team prepares for the game at Cincinnati on Sunday.
Jones, a first-year player, was promoted from the practice squad to the No. 4 spot after rookie Terrence Murphy suffered a season-ending neck injury Oct. 3 at Carolina. Jones didn't have a catch Sunday. He returned three kickoffs for an average of 18.3 yards.
Collins has MRI
Safety Nick Collins underwent an MRI today on his bruised quadriceps muscle. Collins was injured in the third quarter of Green Bay's game Sunday in the Metrodome. Tests of the MRI were not immediately known, Packers coach Mike Sherman said today.
Collins, one of the team's two second-round draft picks this year, was replaced by rookie Marviel Underwood.