Veteran stalwarts Karlos Dansby and Kevin Burnett out. Younger, faster linebackers Philip Wheeler and Dannell Ellerbe in. That was the major change the Dolphins made on the defensive side of the ball, in an effort to infuse more speed into the core of the unit. It was a bold move, but only time will tell if the switch will pay off.
Philip Wheeler - Dolphins beat writers have been buzzing about Wheeler's speed and athleticism, two traits that earned him a sizeable contract from the Dolphins in free agency. He's a solid blitzer and a good tackler, but will need to prove on the field that he's a worthy replacement for Burnett. He'll also need to prove he can make plays on the ball, something he did not do often in Oakland last season.
Dannell Ellerbe - After getting a big contract from the Dolphins this offseason, there haven't been many reports about Ellerbe's performance on the practice field, positive or negative. No news isn't exactly good news for a player the team is hoping makes a bigger impact than his predecessor. Regardless, the veteran is securely a starter and will man the important middle linebacker position in Miami's defense.
Koa Misi - Misi has developed into an extremely solid, if not exciting strong side linebacker going into his fourth year. He lacks the playmaking flare his team is emphasizing but he's a very good run defender and a capable pass rusher when needed. Misi's starting spot is safe.
Olivier Vernon - Though primarily a defensive end, Vernon logged significant snaps at linebacker in his rookie season and will likely dabble this season as well. His skillset fits both positions very well. The Dolphins will use that versatility to disguise their defense by moving personnel to different spots.
Dion Jordan - Like Vernon, Jordan will have the ability to be a hand-in-the-dirt defensive end or a linebacker. To anyone's knowledge, his role hasn't been fully determined and he may primarily play one of those positions. Again, like Vernon, his presence gives Miami the ability to disguise its defense.
Jelani Jenkins - Hasn't generated a ton of buzz so far in camp, but as a mid-round pick, he has a solid hold on a roster spot. Head coach Joe Philbin did mention that Jenkins was doing a good job of picking up the system at the end of last week.
Jason Trusnik, Austin Spitler, Jonathon Freeny - A trio of special team contributors that sparingly play defense, and play poorly when they do. Each is fully replaceable and could be pushed off the roster by an emerging prospect or by an abundance of depth above them.
Josh Kaddu - A 2012 fifth-round pick who spent most of his first season on the practice squad, Kaddu has failed to make a noticeable impact in practices and seems to be falling into the category of replaceable special teams contributor. His roster status is firmly on the bubble.
Practice Squad/Who? Level: