The Green Bay Packers are dealing with a laundry list of injuries, but an apparent hamstring injury to outside linebacker Clay Matthews is clearly the most worrying of the bunch coming from Sunday's 31-17 win over the Arizona Cardinals.
Matthews, second in the NFL in sacks with nine, limped off in the second half and was unable to return. It appeared Matthews was dealing with the injury for most of the game, with several television shots showing him with a noticeable limp.
Packers head coach Mike McCarthy offered little on the severity of the injury or any potential time line of recovery in his postgame press conference. It's likely too early to tell.
Simply put, the Packers can not afford to lose Matthews for any long stretch. What Aaron Rodgers is to the Packers' offense, Matthews is to the defense.
According to Pro Football Focus, no defensive player has graded out as highly as Matthews over the last four seasons, and his 38.5 sacks since 2009 are the most on the team.
Despite the Packers' increased sack total in 2012 (came into Week 9 with a league-high 26), Matthews has still been the cog that runs the machine.
Coming into this week, Matthews' 38 total quarterback disruptions (sacks, quarterback hits, hurries) led the Packers' defensive roster by a staggering 25. Outside linebacker Erik Walden is second on the team with 13.
Losing Matthews could all but dry up a pass rush that depends on Matthews more than any one single player. Backups Dezman Moses and Frank Zombo are a big step down in getting after the passer.
His impact runs deeper than just the pass rush, too.
According to PFF, he's also the team's second-best run defender behind Ryan Pickett through eight games. Matthews' 22 stops, or a tackle that constitutes an offensive failure, is second behind A.J. Hawk.
Another scary factor for Green Bay is that Matthews has suffered problems and nagging injuries with his hamstrings in the past. Who knows how this recent injury ties into those in the past?
The news isn't all bad, however.
Both Matthews and the Packers may have finally "lucked" out injury-wise. With the bye week coming up, Matthews has a full 14 days to rest and heal the hamstring before the Packers are scheduled to play again.
Green Bay travels to Detroit on Nov. 18 for Week 11.
While mostly in the dark on the injury right now, more should be known early next week on the severity of the injury. The Packers would be dealt their biggest injury blow to date if Matthews has to miss a considerable amount of time.