Just look at this year's defense compared to last year, and you'll see there is plenty of reason to be jacked up about what this group could accomplish.
The defensive ends are the same as last year. The defensive tackle spot has added Jeff Zgonina and subtracted Jermaine Haley, which at worse is a wash but probably is an upgrade because Zgonina is a better pass rusher than Haley — or Tim Bowens and Larry Chester, for that matter.
At linebacker, the Dolphins have replaced starter Derrick Rodgers with Junior Seau and second-round pick Eddie Moore either will back up or replace Morlon Greenwood at strongside linebacker. That's a significant upgrade at that position.
And remember that this defense finished third in the NFL in total yards allowed last season.
Now the question is where Knight will line up. The logical assumption is that he will replace Freeman as the starter at strong safety, but don't be shocked if he winds up taking over for Marion, who didn't have a great 2002 season and whose spot on the roster might not be as firmly entrenched as some people might think.
Either way, the presence of Knight was another good boost for an already-impressive defense.