A strong run defense gave way to a shaky pass defense, and their coverage ability was out-paced considerably by their ability to stop the run. It creates a shaky picture, and one that needs to be cleared up quickly, considering how powerful the Steelers' offense currently is. Maximizing their team strength on offense will rely on a level of defensive improvement that will have to see new faces again next season. Read the offensive grades here.
The meltdown of extension-receivier Cortez Allen is impossible to ignore here, but a solid season from CB William Gay and a few rays of optimism from Antwon Blake don't make this year a total loss. It is definitely an area of improvement for a team that will need to re-invest a bit in their secondary this offseason. Mike Mitchell's apparent groin injury couldn't have helped him, and outside of the useless argument of whether he gets a "pass" for the year or not, or even whether he was injured or not, the team will need more out of him in 2015. This will most likely have been Troy Polamalu's final year with the team, so ready or not, Shamarko Thomas will take actual defensive snaps next year. He will have to do a lot more than just take snaps too.
The plus part of this is only due to the resurgence the team saw toward the end of the season through the insertion of Stephon Tuitt and the continued improvement from defensive end Cameron Heyward. Look for an extension to come Heyward's way in an effort to lower his cap number a bit, and he should now be the unquestioned leader of that defensive line. Tuitt's continued improvement will be critical if this team is actually able to find a way to create consistent pressure, but the real story here is in the absence of edge rush. James Harrison played well in a few games but was shut out of a few others and isn't likely to return. Jason Worilds will not be back and the team will likely have to pay out for the services of Arthur Moats on a multi-year deal. Combine that unknown (although Moats was an effective pass rusher, his run support wasn't challenged much, likely the reason he wasn't on the field much) with the unknown of Jarvis Jones, and you have the real point of trepidation on this team. It isn't the coverage, it's the rush.
The real difference between 2013 and 2014 was a lesser amount of big runs allowed. It isn't perfect yet, but excellent performances late in the year against a good Chiefs rushing team as well as a second half-adjusted performance against Baltimore in the playoffs (they didn't allow Justin Forsett one rushing yard in the second half) give off a sense of optimism for the future. Steve McLendon's low dead money hit combined with a higher cap charge put him in a precarious spot, but when healthy, McLendon has been a solid player. He should return, but moves still need to be made on this defense overall.
The value of Heyward shows the most here, as the play of Cam Thomas was enough to warrant a considerable adjustment. Heyward came on as the year went on, and the combination of Heyward and Tuitt looks to be a powerful force in 2015. Injuries are a concern for McLendon, but he was a solid player when healthy. Brett Keisel, before injury, wasn't solving any problems but provided a reasonable stop-gap until Tuitt replaced him. The advancement of McCullers will be a key this offseason.
This may be a step high, but the production of Timmons along with the combined play of Moats, Worilds and Harrison as well as the triumverate of Sean Spence, Vince Williams and Ryan Shazier create something of a muddled picture overall. Solid, not outstanding group of linebackers. The Steelers will need to see significant improvement from Jones and Shazier next season, and outside linebacker will remain a question.
There isn't much keeping this from falling further, and the team will need to make a few replacements this offseason. Polamalu shouldn't be expected back, he's due far too much money for the production he had (first year in nearly a decade without an interception), so the team will trot into next season with only two starting positions in their base four secondary; Gay and Mitchell. Expect these positions to be addressed in the draft and they're going to need to find guys who can play right away, and play well.