Five things you need to know about the Dolphins:

1. The Dolphins don't need to be talked about: When examining the AFC East, the teams to beat are the New England Patriots because of their consistency and the New York Jets because of their ubiquity. Often overlooked are the Dolphins, who won the division two seasons ago and were mathematically alive for a wild-card berth heading into Week 17 last year. The Dolphins have made some splashy moves in the offseason, signing receiver Brandon Marshall and inside linebacker Karlos Dansby. But you won't hear the Dolphins yapping about themselves or talking any trash. They're good, and they're happy to prove it on the field.

2. Chad Henne has to show what he can do: Henne took some lumps last year, his second in the NFL and first as a starter. He was thrust into the huddle when Chad Pennington went down with a season-ending shoulder injury in Week 3. Henne at times showed why the Dolphins believe he's their franchise quarterback. But over the final six games, with their season on the line, Henne threw six touchdown passes and 10 interceptions. A season of experience plus a full offseason preparing as the starter plus Marshall should help Henne blossom. But if he doesn't, Pennington provides a terrific backup plan.

3. Questions abound on Miami's revamped defense: New defensive coordinator Mike Nolan should make a significant impact, but he has a lot of issues to deal with. How much has the defense changed? Only two players from last year's front seven -- defensive end Kendall Langford and inside linebacker Channing Crowder -- are expected to be in the same place on opening day. They've shifted Randy Starks from end to nose tackle, where he will be undersized but quicker than the traditional 3-4 centerpiece. Outside linebackers Cameron Wake and rookie Koa Misi have one combined NFL start. Sophomore cornerbacks Vontae Davis and Sean Smith are prone to giving up big pass plays.

4. One of Miami's biggest strengths comes with serious concerns: One could argue the Dolphins have one of the NFL's best 1-2 backfield combos. Ronnie Brown and Ricky Williams are dangerous runners. Brown is a multidimensional threat as a receiver and Wildcat conductor. Williams rushed for 1,121 yards and averaged 4.7 yards a carry, one-tenth of a yard off his career high. So what's the problem? Brown can't stay healthy. He has played 16 games once in his career and is coming off a broken foot. Williams is 33, and the list of running backs who got old overnight in their early 30s is longer than Browns' list of injuries.

5. Miami's interior O-line is like the Bermuda Triangle: Maybe there's some sort of vortex players keep getting sucked into because the Dolphins have struggled to find any consistency at center or guard since Bill Parcells, Jeff Ireland and Tony Sparano took over the roster. In their third season together, they probably will be on their third center (Samson Satele to Jake Grove to Joe Berger) and on opening day could start two guards (Richie Incognito and John Jerry) who weren't on their roster last year. The Dolphins have sunk considerable bucks into their interior line, signing free agents Justin Smiley (no longer on the team) and Grove (second on the depth chart). Somebody please call Robert Stack to help explain.

-- Tim Graham, ESPN.com