Surprisingly, the Broncos' defense played rather solid last year. They transitioned to a 3-4 scheme, and it clearly paid off.
Their defensive line, while not great, should improve. Even though, Williams is 35 years old and coming off an injury, he can still be an effective two-down player.
Alongside him will be Justin Bannan and Jarvis Green, both of whom have had relative success in similar schemes. Overall, they are nothing special but should be able to hold their own.
However, their back seven is very talented. Elvis Dumervil emerged as an elite pass rusher, amassing 17 sacks. Opposite him, Robert Ayers has yet to develop as he struggled, both, in generating a pass rush and in coverage.
In the middle, though, they don't have much. D.J. Williams is talented, yet appeared out of place in the new scheme. Next to him, Mario Haggan and Akin Ayodele will compete for the starting duties.
Their secondary, despite their old age, was a strong group. Corner Champ Bailey had one of the best seasons in his career, and Brian Dawkins proved he can still make plays at safety. Andre Goodman and Renaldo Hill also had solid performances.
I think the defense may take a hit with the loss of Mike Nolan. He's definitely one of the best defensive coordinators in the business.