The NFC North is blighted by some of the softest pass defense in the NFL. The Green Bay Packers took division with a 15-1 record last season, despite ranking last in the league against the pass.

Here are the major weaknesses troubling the NFC North heading into the 2012 NFL season:

Chicago Bears: Offensive Line

Although the Chicago Bears ranked 28th in pass defense last season, count on their Tampa-2 scheme to tighten things up in 2012. The Bears' real weakness is the play of their offensive line.

Chicago's front five surrendered 49 sacks last season, after giving up 56 in 2010. Quite how those numbers recommended line coach Mike Tice for a promotion to offensive coordinator, is anybody's guess.

The Bears have some talent at the skill positions, particularly running back Matt Forte. They traded for wide receiver Brandon Marshall and added another tall flanker in the draft, with the selection of Alshon Jeffery.

However, all of those weapons will be rendered moot, if the Bears don't perform better up front.

Detroit Lions: Secondary

It's difficult to fathom why the Detroit Lions didn't use their first pick in the 2012 NFL draft on a cornerback. The Lions may have ranked highest in the division in pass defense, finishing 22nd overall.

However, that ranking can be attributed to a talented front four that applies constant pressure. When it counts, the Lions secondary is abysmal.

Former Packers backup quarterback Matt Flynn threw six touchdowns against them in the season finale. One week later, Drew Brees beat the Lions coverage schemes for 466 yards in the NFC Wild Card Playoffs.

Head coach Jim Schwartz will be relying on the fitness of safety Louis Delmas, to make his zone system work. However, there is no doubt the Lions should have done more to address their secondary this offseason.

Green Bay Packers: Secondary

Opponents simply annihilated the Green Bay Packers through the air in 2011. Defensive coordinator Dom Capers couldn't mask the deficiencies in his secondary, no matter how many fire zone-based, pressure packages he came up with.

Capers and the Packers clearly feel that increasing the pressure up front is the best way to fix the problem. They selected rush end Nick Perry and defensive tackle Jerel Worthy in the draft, to boost their pass rush.

Sticking with basically the same secondary that struggled to cover anyone in 2011, is a major gamble.

Minnesota Vikings: Secondary

Just how does a team lead the NFL in sacks and still have an abysmal pass defense? Only the Minnesota Vikings can answer that perplexing question.

The Vikings defense was 26th against the pass and the numbers would have been even worse, without the pressure put on by Jared Allen and company.

At least the Vikings took steps to remedy the issue in the draft. They used high picks to select safety Harrison Smith and cornerback Josh Gordon.

Head coach Leslie Frazier needs the youthful duo to make an immediate impact, if the Vikings have a chance of escaping the NFC North basement.