The most important thing is to keep every member of the Green Bay Packers healthy. From Tom Fanning at Packers.com:
Head Coach Mike McCarthy said wide receiver Jordy Nelson sustained a bruise to his side, linebacker Clay Matthews tweaked his hamstring, and wide receiver Brett Swain sprained his knee during the Family Night scrimmage. McCarthy said it was too early to judge the severity of the injuries.
Greg Bedard tweets that Swain said it was just a "scare" and his knee is fine. Obviously Nelson and Matthews are important to the team, but neither injury sounds serious.
The Press-Gazette has posted a bunch of photos if you are so interested.
UPDATE: From the Journal-Sentinel, CB Josh Bell is on crutches after a right foot injury, and he's scheduled for an MRI. He was signed late last season after the injury to CB Al Harris, and didn't play a whole lot, but he was in coverage on the game losing TD pass in Pittsburgh last season. He's in the mix for a spot at the end of the bench, but not a lot was expected from him this season, if this turns out to be serious.