The Packers defense was a big part of that success, and with stars like BJ Raji, Clay Matthews, Charles Woodson and Tramon Williams, among others, they came into this season with high expectations once again.
Although the Packers are currently undefeated (pending the game with the Atlanta Falcons tonight), their defense has been surprisingly suspect this season, namely in the passing game.
Green Bay has been strong against the run this year, allowing just 71 yards per game, which is good for second in the nation.
However, the secondary is a completely different story. Allowing an incredible 335.8 passing yards per game, the Packers are last in the NFL in pass defense.
Considering how good Green Bay's secondary was last year, that's some kind of conundrum.
One of the biggest reasons seems to be the loss of Nick Collins, who many believe is the best safety in the NFL. Tramon Williams has also been injured lately. Given the amount of depth the Packers have in the secondary, though, the complete 180 is difficult to understand.
Furthermore, any secondary's best friend is a strong pass rush, and with one of the top outside linebackers in the NFL in Clay Matthews, you would think they'd be getting that pass rush.
Nevertheless, the Packers have been giving up 406.8 yards and 24.2 points per game, ranked 27th and 16th in the NFL, respectively.
At this point, there's no reason to fret about the 4-0 Packers' defensive struggles (though as of about 9:15 on Sunday night, the Falcons are ahead 14-6).
However, if the secondary continues its poor play and Green Bay can't continuously outscore opponents, the Pack may find themselves in a little bit of trouble.