"Behind Enemy Lines" is a Thursday post on the Access Vikings blog. In advance of Sunday's Vikings-Green Bay game, Dan Wiederer of the Star Tribune interviewed Tyler Dunne, who covers the Packers for the Milwaukee Journal Sentinel. Here are three things you need to know ...

1 The Packers are far from unbeatable.

At 7-4, Green Bay already has lost three more times than it did during the entire 2011 regular season.

The Packers defense -- operating right now without key starters Clay Matthews (hamstring), Charles Woodson (collarbone) and Sam Shields (shin/ankle) -- had few answers and surrendered scores on six of the Giants' first nine possessions in a 38-10 loss on Sunday.

On offense, meanwhile, Aaron Rodgers threw for 219 yards and was sacked five times. Defenses have had success against Rodgers this season by rushing only four and keeping the safeties deep to take away the big play.

"First things first," Dunne said, "you have to try and get pressure by rushing only four and not needing to blitz. Rodgers reads the blitz so well that any team that goes that route frequently does so at its own peril.

"But when defenses have sat back and taken away the deep ball, they've been able to force Green Bay into this game of small ball. Rodgers will stay patient; he's not going to force things. But that also creates a ton of frustration because nothing ever really opens up."

2 The Packers' offensive line is in disarray.

Four weeks ago, right tackle Bryan Bulaga injured his hip and was placed on injured reserve. That forced a move in which left guard T.J. Lang had to shift outside to tackle and Evan Dietrich-Smith supplanted Lang inside.

"Lang had really settled in at guard," Dunne said. "He had a very nice year last season there. He got himself a contract extension. That was his spot. And now he's out at tackle. He's played there a little before, earlier in his career. But it's still a huge adjustment."

Smith, meanwhile, can be manhandled at times. And veteran center Jeff Saturday, a five-time Pro Bowler in Indianapolis who signed with the Packers last spring, just hasn't provided the same level of production as his predecessor, Scott Wells.

"Saturday can be solid because he knows how to run an up-tempo offense," Dunne said. "But overall, this line is just not as good as it was last year. That's been obvious."

3 Big doubts remain as to whether the Green Bay defense has enough of an edge to aid a deep postseason run.

Said Dunne: "The question that seems to be hanging there is 'Are they physical enough, are they tough enough to really compete with the 49ers and the Giants?' In those two games, they really got pushed around. And those are the two teams that played for the NFC Championship last year."

The 49ers rolled to a 30-22 victory in the season opener. The Giants won by 28 last weekend.

On the plus side, the Packers are seeing noticeable growth from young defensive backs Casey Hayward, Davon House, Jerron McMillian and M.D. Jennings. But the way Eli Manning and Hakeem Nicks flourished last Sunday, there's reason for concern.

"When you get beat 38-10 by a team that ended your Super Bowl hopes the year before, you better be concerned," Dunne said.