"I think it won't be bad. I'm looking at four to six weeks at most," Jackson said after the game.
Losing Jackson would be a huge loss for the Packers. Before being signed at midseason last year, the Packers were allowing 117 yards per game on the ground. With Jackson, the Packers allowed 95 per game.
"We need him bad. Real bad," safety Darren Sharper said.
Cullen Jenkins and James Lee filled in for Jackson, and Packers coach Mike Sherman said he does not know how serious the injury is or how much time Jackson may miss.
The knee will be examined after the swelling goes down. Jackson had surgery on his right knee during the off-season.
RB Najeh Davenport strained his hamstring on a kickoff return midway through the second quarter. His status for Sunday's game vs. Chicago at Lambeau Field is unknown.
Davenport was plagued by hamstring problems during training camp.
Safety Mark Roman gave the Packers a scare when he had to leave the game in the second quarter. A replay showed that he may have taken a helmet to the ribs as teammate Bhawoh Jue dove in to aid in a tackle. The Panthers scored a touchdown on the next play with Roman on the sideline. But Roman, the Packers' best free-agent gain this season, returned to make a TD-saving tackle in the third. After both Darren Sharper and Michael Hawthorne neglected Ricky Proehl, Roman was the only man between Proehl and the end zone. Roman cut over to upend the former Bear receiver after a 34-yard gain. Barnett picked off Delhomme two plays later.
C Mike Flanagan peformed admirably as part of the Packers' formidable offensive line, but after sitting out training camp and most of preseason due to patellar tendinitis, Flanagan had to come out early to rest and ice his knee.
"His knee was a little sore and I was able to rest him," Packers coach Mike Sherman said.
The biggest hit of all was absorbed by the Panthers. Pro Bowl wide receiver Steve Smith broke his left leg late in the fourth quarter. With Carolina down 17 in the final minutes, Smith caught a short pass and was trying to get out of bounds when he was grabbed from behind by Packers linebacker Hannibal Navies. Smith's leg got caught underneath him as he was being dragged to the turf.