Mike McCarthy announced that WR Greg Jennings has a foot injury. From Packers.com:

OK, I’ll start with the injuries. Brandon Chillar re-injured his shoulder. He will be out this week. Spencer Havner had a hamstring strain. He will also be out this week. Dimitri Nance suffered a concussion. He will go through the normal process there throughout the week. Greg Jennings had a foot strain. I anticipate he will miss some practice time. And Patrick Lee had an ankle sprain. He will be challenged to be back this week. With that I’ll take your questions.

At this point, it's too early to tell whether Jennings will miss next week. Not even the Packers know for sure. But my best guess is that he won't miss a game. Nance and Lee could return, but the absence of either won't make much of a difference.