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The Oakland Raiders will depend on a pair of rookies to compensate for roster attrition and weaknesses within the front seven.

According to NFL.com’s Ian Rapoport, the Raiders placed defensive end Justin Tuck on injured reserve with a torn pectoral muscle suffered in Week 5 against the Denver Broncos.

To put Tuck’s importance in perspective, he ranked 11th overall among 51 defensive ends in a 3-4 alignment, per Pro Football Focus. He’ll likely continue to provide vocal leadership behind the scenes and from the sidelines, but his on-field production comes to an end in 2015.

Mario Edwards Jr.

It’s the next-man-up mentality for the Raiders, and rookie defensive end Mario Edwards Jr. must take on an expanded role from Week 7 onward. Oakland’s second-round pick brought some cheers and skepticism on draft day.

Edwards’ skill set as a gap-stuffer and run-stopper at Florida State didn’t fulfill Oakland’s need for a pass-rusher at first glance. The rookie faced scrutiny for his lack of flare and fire on the field in his college years and came into the league with something to prove, per CSNBayArea.com’s Scott Bair:

I just want to show everybody that’s pretty much the past as far as weight issues and everything that happened in college or whatever. The Raiders believed in me, and they gave me an opportunity and a chance and that’s all I needed – an opportunity to go out there and prove myself.

Typically, second-round picks come in with moderate to high expectations, but Tuck remained the unquestioned starter at defensive end throughout training camp and the preseason. Either Benson Mayowa or Denico Autry started on the opposite side of Tuck, depending on the formation, during the preseason.

Attrition struck the Raiders defense early, starting with Mayowa’s knee injury in the final preseason game against the Seattle Seahawks. Defensive coordinator Ken Norton Jr. transitioned to the 3-4 in Week 3 but opted to use Autry over Edwards.

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Autry suffered a concussion in Week 4, which put Edwards in position to play extra snaps. Tuck’s season-ending pectoral injury places the rookie defensive end in the starting lineup for the long term.

Edwards spoke to local reporters about his extended role in Week 5 with a calm demeanor.

“Me being versatile enough to go up and down the line is always good," Edwards said. "It was comfortable being in there. Things just happen a little quicker, so I had to react to it.”

The 3-4 alignment fits Edwards' strong suit, putting him in position to contain the rushing attack and use his athleticism against slower offensive linemen. In his first shot at significant playing time, he recorded four tackles and a sack on Broncos quarterback Peyton Manning.

Neiron Ball

The Raiders' fifth-round-pick also faced skepticism for his potential role with the team. Oakland selected two linebackers within the same round. Ben Heeney came off the board as the No. 140 overall pick, and Neiron Ball was the No. 161 overall pick.

Heeney flashed during the preseason as Ball continued to work hard on the practice field. Based on preseason production, it seemed as though the inside linebacker from Kansas would earn a shot at extensive playing time before the mentally tough linebacker out of Florida who underwent microfracture surgery approximately six months prior to the draft.

Some suggested that Heeney should take the field to remedy the Raiders’ tight end coverage issues:

Norton went in another direction, and for good reason.

During the preseason, Heeney missed six tackles and allowed nine catches out of 11 targets and a touchdown in coverage against second-unit offenses. He’s a solid run-stopper, but he's far from the solution to the Raiders' tight end issues.

In Week 5, the Raiders shut out the Broncos tight ends in receptions. In an interview with reporters, Ball didn’t take all the credit for stopping the stampede of tight ends running free down the middle. He acknowledged team effort.

“I feel like the [defensive backs] did their job to cover their man, and the guys that were pass rushing the quarterback did their job, and it all just worked together. It wasn’t just a one-man effort.”

Ball stopped short of saying the coaching staff gave him the green light as a starter going forward, but he felt he accomplished enough to warrant more time on the field.

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Inside linebacker Curtis Lofton has been targeted 16 times in coverage over the first five weeks. All 16 targets were converted into receptions and two for touchdowns. He’s clearly struggling to defend the middle of the field. Ball should expect to step in on obvious passing downs.

Lofton once played a vital role as a run-stopper. According to Pro Football Focus, he grades as a minus-1.9 in run defense. Norton may opt to limit his snaps or lean on Ball to maintain the Raiders’ stout fourth-ranked rush defense. The rookie linebacker has potentially found a niche as a coverage linebacker that serves as his claim to a starting spot next to Malcolm Smith.

Oakland will need both Edwards and Ball to maintain its stone-wall identity up front. According to Team Rankings, the Raiders allow 83.2 rushing yards per game. Opposing teams decided to throw frequently to compensate for the inability to establish a ground attack.

The middle of the field became a hot spot for coverage exploitation, but the decision to utilize Ball’s coverage skills further limits vulnerable areas within the Raiders defense. The secondary still needs configuration, but opposing running backs and tight ends won’t use the Raiders’ interior defense as a doormat going forward.

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All statistics are provided by Pro-Football-Reference.com, Pro Football Focus and Team Rankings unless otherwise noted.

Week 5 statistics and play-by-play analysis is provided by NFL.com.