I think we actually had 3 key injuries total.
On offense, RT Brown.
Without Brown, Polumbus was the most inconsistent and least competent lineman out of the whole O-line bunch. He gave up the most sacks, hurries, and had the most missed assignments per pro football statistics. Kory Lichtensteiger was not that far behind him; I believe Kory had the most penalties of the entire O-line but that is a different story.
Many people have said the loss of Fred Davis was a critical too, but Paulson was steady and competent. Davis led the team in catches at the point he went down in the game 7 loss to the Giants.
In 7 games Davis had 24 catches for 325 yards or 13.5 yards average per catch and a long one for 29 yards. Davis had no TD catches.
In 10 games Paulson had 25 catches for 308 yards or 12.3 yards average per catch and a long one for 31 yards. Paulson had 1 TD catch, and I am not talking about the TD catch in the playoff loss to Seattle. I don't see that big of a difference between the two based upon these stats.
On defense, losing Carriker and Orakpo were the two key injuries.
Our front seven was supposed to be our strength. Our safety situation was a mess at the beginning of the season. When you have two new starting safeties, neither of which was on the team the year before and both had huge question marks, you don't call that an ideal situation or even a comfortable situation. Also, you can't "what if" when the two projected starters have nothing to use to compare them. No, our defensive problems started when Carriker and Orakpo went down and our strong front seven turned into a strong front five.
Kerrigan got 9 sacks this year. He had 1 sack in each of the first 2 games. After Carriker and Orakpo went down in game 2 he got 2 1/2 sacks and 1 interception in the remaining 7 games before the bye. It took him 7 more games to get the same amount of sacks he had after only 2 games.
Regarding Kerrigan's remaining 4 sacks on the year after the bye, 3 of them came in the two games we played against Philly and the other one was against Dallas on Thanksgiving.
Orakpo was well on his way to having a banner season. Go back and look at the statistics for the 2 games he played in. He had 1 sack and 1 forced fumble after 2 games - both of those were against the Rams in game 2 before he went down.
In the remaining 5 games before the bye, when the coaches hadn't yet figured out what they were going to do without Orakpo and tried an LB by committee approach, Rob Jackson had a total of 1/2 sack. After the bye, he had 4 in the remaining 7 games of the season.
Lorenzo Alexander had 1 1/2 sacks before the bye, but that was all against Minnesota; after the bye just 1 sack against Philly.
Chris Wilson played heavily in games 3-6, sparingly after that, but was ineffective and ended the year with only 1/2 sack.
I think Rob Jackson did a great job and made a definite impact on defense once he was made the starting ROLB; he had 4 interceptions this year, but Orakpo would have had a bigger impact and would have influenced the outcome of games had he been healthy and played the whole year.