Here are the individual grades; as always, with a greater role comes greater responsibility, so more is expected out of the starters than reserves, more out of veterans than rookies, more out of the highest than lowest paid players...
Clay Matthews, III: A+
Matthews was drafted to be a Packers starter, but not projected to make it there by Week Four, much less be a talented unit's best player by a wide margin. If he stays clean and healthy, Matthews may well be the Packers best player on either side of the ball before his rookie contract expires.
One of the chief reasons for him being in the lineup so fast was not his exceptional pass-rushing--he was tied for fifth among linebackers in sacks with 10 even with only 13 starts--but for his run-stuffing capabilities. And once inserted into the lineup, the Packers run defense did drop about 20 yards per game in rush defense, ending as the top in the league in total yards and 90th percentile in yards per carry.
But of course, that was secondary to what Matthews provided in big plays. Only four linebackers had more sacks, only one of those also forced three fumbles (tied for most at the position), and only four others had touchdowns. Inexplicably, Matthews was only a Pro Bowl alternate and was a runner-up for defensive rookie of the year to former USC teammate Brian Cushing despite Cushing testing positive for performance enhancing drugs.
Brad Jones: A
A lot of Packers fans and even some experts were calling for the Packers to upgrade the position opposite Matthews, but Ted Thompson said himself following the draft that while he understands people seeing that as a position of need, he feels the team is more set at the spot than that. Jones is the reason for both opinions--as a seventh-round pick, he did not inspire a lot of confidence; however, his ability to crack the starting lineup and play effectively did, and he should only get better as he gets more experience.
Jones only started seven games and still managed four sacks, 26 tackles, and seven assists: Only nine linebackers in the league last season had over eight sacks that pace would project to. Moreover, he fared well in coverage, as backs and tight ends no longer burned the Packers as they had in the first half of the season.
Cyril Obiozor: B-
Obiozor did very little, seeing very limited action in just five games--the sum of his statistical accomplishments were two tackles. However, as a practice squad player and undrafted free agent in 2009, simply getting onto the field of an elite component of an elite NFL defense is overachieving.
Aaron Kampman: C+
Kampman was not the disaster many Packers fans have made him out to be in making the transition from defensive end in the 4-3 to outside linebacker in the 3-4. He had 3.5 sacks through the eight-plus games he played before being injured--tops on the team at the time. Despite the half-season, his 30 tackles and 12 assists were lower than only eight and four Packers, respectively. He even covered a wide receiver in the slot on one play in memory, showing progress in the area he most lacked.
Nevertheless, no Packers fan should lament his signing elsewhere, as he was clearly a better fit for end in a 4-3. He may not have been a disaster in the new role, but he was no longer the Pro Bowl player he had been; in fact, the defense got better when he was replaced by Jones.
Brady Poppinga: D
The Stormin' Mormon was a starter for four years coming into the season and began the year in the same position. After the defense struggled and he managed just six tackles and five assists, he was replaced by super-rookie Matthews. By mid-season when Kampman went down, the team had more confidence in a seventh-round draft pick than a four-year starter--that is as telling as the difference in the defensive play after Poppinga was essentially the only replacement before Week Four.
Still, Poppinga is a capable back-up who finished with 16 tackles, seven assists, and a sack. Now that he is 30 and the Packers have so much talent and depth at the position, it is unlikely he will stick around, but the team could keep him knowing he is serviceable both inside and out.
Jeremy Thompson: FI hate to give a player who gets hurt an F, but Thompson was projected to start at the position opposite Kampman in spring camps last season, and was healthy enough to be active for six games. If you are a projected starter or even frequent platoon-player who cannot get more than one tackle in six games active, you cannot get a passing grade.