The AFC North is arguably the NFL's toughest division. In 2011 all four teams ranked in the top 10 for total defense and the division sent three representatives to the AFC playoffs.

Here are the key weaknesses that may hold the rugged AFC North back during the 2012 NFL season:

Baltimore Ravens: Play calling on offense

Despite making it to the AFC Championship game, the Baltimore Ravens often find a way to confound themselves. That way usually involves some questionable play calling on offense.

Coordinator Cam Cameron seems determined to make quarterback Joe Flacco the focal point of the Ravens' attack. The problem is that this desire often comes at the expense of the unit's best player, running back Ray Rice.

In a Monday Night defeat to the Jacksonville Jaguars in Week 7, Rice had only eight carries. The disturbing pattern was repeated in a Week 10 loss to the Seattle Seahawks, where Rice was given just five carries.

These are both teams the Ravens should beat. Despite the investment in 2008 first-round pick, Flacco, the Ravens are still a running football team.

Cincinnati Bengals: Run Defense

During the regular season the Cincinnati Bengals ranked a respectable 10th in the league against the run. However, a soft underbelly was exposed at crucial times.

The run defense undermined the Bengals in two painful defeats to division rival the Baltimore Ravens. Ray Rice tallied 295 yards in those games, including a 191-yard effort to finish the season.

In the AFC Wildcard playoffs, the Cincinnati defense surrendered 153 yards to Houston Texans ace Arian Foster. If they are going to compete in a run-heavy division, the Bengals must stop handle the ground game with more consistency.

That reality is probably what prompted the team to draft Devon Still and Brandon Thompson, to add to an already deep defensive tackle rotation.

Cleveland Browns: Quarterback

The Cleveland Browns own run defense was abysmal in 2011. However, even with improvement on that side of the ball, the Browns will only go as far as their quarterback can take them.

Who that quarterback will be, is the major question. 22nd overall draft pick Brandon Weeden probably has the edge. The 28-year-old rookie has the physical tools, but will need to refine some raw aspects of his game to suit the pros.

If Weeden is not ready to start immediately, then last year's starter Colt McCoy will probably remain in place. McCoy is competitive, but maybe lacks the speed of thought and timing, needed for head coach Pat Shurmur's West Coast-style passing game.

The Browns have to find a quarterback who will complement top rookie running back Trent Richardson.

Pittsburgh Steelers: Offensive Line

The Pittsburgh Steelers need to force more turnovers, after registering a -13 ratio in 2011. However, their biggest weakness is still likely to be a shaky offensive line.

The group allowed 42 sacks last season. While many of those are attributed to quarterback Ben Roethlisberger's habit of holding onto the ball, it's still too many for a team with serious Super Bowl ambitions.

They added guard David DeCastro and tackle Mike Adams with their first two draft picks. Head coach Mike Tomlin will be hoping this duo can form a formidable young nucleus with center Maurkice Pouncey.