Decimated D: Shaughnessy to miss 8 games with knee injury

Linebacker Matt Shaughnessy will miss at least eight weeks with a knee injury suffered Sunday against the Broncos.

If Las Vegas sports books were into morbid betting lines, they might create the following: Which Cardinals defensive starter is the most likely to play the entire 2014 season?

The Cardinals got a sliver of good news on Monday when an MRI revealed an MCL strain in defensive end Calais Campbell’s right knee that should sideline him for one to three weeks, slightly shorter than the three- to four-week projection coach Bruce Arians initially cited after Sunday’s game.

But the defense took another hit when Arians announced outside linebacker Matt Shaughnessy, a terrific run defender, would miss six weeks of practice after being placed on the injured reserve, designated for return list with cartilage damage in his knee. Shaughnessy played 58 defensive snaps in Denver. The IR designation will sideline him at least until the Cardinals play Kansas City on Dec. 7. Players on the list must miss eight games.

To recap, six of the seven starters from last season’s final front seven are out of the lineup. In addition to Shaughnessy and Campbell, defensive end Darnell Dockett is out for the season with an ACL tear, outside linebacker John Abraham is on IR with recurring concussions symptoms, inside linebacker Daryl Washington is suspended for the season for violating the league’s policy on substance abuse and inside linebacker Karlos Dansby is wearing a Cleveland Browns uniform.

That doesn’t even take into account the fact that free safety Tyrann Mathieu has only taken 35 defensive snaps this season as he recovers from offseason knee surgery, or the quarterback situation where the Cardinals are in a holding pattern with starter Carson Palmer (shoulder nerve) and Drew Stanton (concussion). 

If the Cardinals sign another quarterback later this week, you’ll know they’re not feeling good about either player’s chances of playing Sunday against Washington, which would mean either rookie Logan Thomas or a veteran who doesn’t know the offense. 

In other words, two bad options.

RELATED: NFL confirms that Calais Campbell’s injury occurred on illegal chop block by Julius Thomas. STORY >>

When asked if this was starting to look like that infamous season in Indianapolis when his players were dropping like flies, Arians disagreed.

"Oh, it’s not that bad yet," he said. "I mean, I know everybody’s name."

Arians said Alex Okafor would take Shaughnessy’s spot in the starting lineup. Okafor just returned to playing health from a thigh tear that had hampered him all season. He missed most of last season with a torn biceps tendon.

Arians said the team will use a rotation to replace Campbell, with rookie Kareem Martin (65 defensive snaps Sunday) Tommy Kelly (68), and Dan Williams all factoring in.

— Cardinals running back Jonathan Dwyer on Monday pleaded not guilty to to aggravated assault charges. Dwyer was arrested Sept. 17 and accused of hitting his wife on two separate days in July. 

— Arians said punter Dave Zastudil re-injured his groin Sunday, a problem that has hampered Zastudil all season. The Cardinals have punter Drew Butler on the practice squad if necessary.

— Tight end Troy Niklas suffered a high-ankle sprain and is listed as day-to-day, although that type of injury normally takes a few weeks to heal. Arians thinks cornerbacks Patrick Peterson (ankle) and Justin Bethel (shoulder) will be OK.

Follow Craig Morgan on Twitter