The Oakland Raiders had one of the worst passing-defenses in 2011, yet their so-called rebuilding year was a major improvement from the year before.

With the unexpected firing of head coach Hue Jackson, and the new era of general manage Reggie McKenzie set to begin, the Raiders have a lot to look forward to this season. However, they still need to make crucial improvements if they want to have any chance of winning the division this season.

Peyton Manning has stolen the spotlight of the AFC West the last couple of months, but the Raiders have quietly begun patching up holes to become a contender in the division.

Starting with the hiring of a rival defensive coordinator, McKenzie and the Raiders made the bold decision to go against the grain and select a defensive-minded coach to bring in the new era of black and silver.

Dennis Allen is the first defensive coach hired by the Raiders since the late Al Davis hired John Madden in 1969.

Allen, who looks to bring the Raiders back to their glory days, has a tough road ahead, and it all begins with the defense.

The first improvement needed, as mentioned before, is the simply self-destructive passing defense.

Last season, the Raiders were ranked 27th in the league, and managed to give up over 4,000 yards passing. The secondary was hit hard when the Philadelphia Eagles signed Nnamdi Asomugha, and now having to play in a strong quarter-back division, necessary adjustments are crucial.

Perhaps one of the least talked about, yet important acquisitions this offseason was the Raiders signing of former Rams cornerback Ron Bartell.

Although only signed to a one-year, $3 million deal, Bartell can immediately provide a veteran-like stature that is missing in Oakland's secondary.

Bartell is a very physical corner who cares more about knocking down the ball that giving up space to go up for the pick. In his career, Bartell has accumulated over 54 knockdowns in pass coverage.

He is extremely fast at his position, yet has been plagued by unfortunate injuries early in his career, which is why the Raiders were a little skeptical to sign him to a long-term deal. Regardless of the possibilities, Bartell has proven to be a threat to many receivers throughout the league.

He is a good all-around corner that is basically effective in any style of defense that Allen is ready to throw on the field.

Wrapped in a schedule in which they will have to face the throwing powers of Manning, Philip Rivers, and Drew Brees, Allen, along with the entire Raiders defense, have a difficult task at hand.

The Raiders will open up their regular season on Monday Night Football against the San Diego Chargers on Sept. 10.