Quarterback
Tannehill took steps toward being the franchise quarterback Miami has lacked since the departure of Hall of Famer Dan Marino in 1999. Tannehill's biggest problem in 2013, however, was occasional indecision and an inability to connect on deep passes. Veteran Matt Moore returns as the No. 2 quarterback, and Pat Devlin and rookie Brock Jensen will vie for the third spot on the depth chart.
Running back
Lamar Miller and Daniel Thomas were given multiple chances to become the lead back, but neither capitalized on his opportunities. Former Denver Bronco Knowshon Moreno was signed to become the new starter, but he has been limited by a troublesome knee injury during offseason workouts and may need surgery.
Wide receiver
If Wallace can become a legitimate deep threat, the offense could see a big boost. Philbin said of Wallace, "(He is) doing the little things that can make the difference when the season comes around." With Brian Hartline entrenched on the other side, the Dolphins would like to see Rishard Matthews become a consistent third option. Rookie Jarvis Landry might make his biggest mark on special teams but is versatile enough to play in the slot or on the outside.
Tight end
After a strong 2013, Charles Clay could become one of the NFL's top young tight ends. Dion Sims registered six receptions, 32 yards and one touchdown in 15 games last season as a rookie but could become a regular contributor after his first full offseason.
Offensive line
The line will have four new starters, with center Mike Pouncey as the only likely 2013 holdover. But Pouncey likely won't be ready for Week 1 after having hip surgery Monday. Sam Brenner is Pouncey's probable fill-in. On the positive side, Pro Bowl left tackle Branden Albert was signed from the Kansas City Chiefs, and rookie right tackle Ja'Wuan James, whom the team drafted with the 19th pick, has impressed in organized team activities. Ex-St. Louis Rams backup Shelley Smith and second-year player Dallas Thomas are being counted upon to come through in their first chances to be full-time starters at guard.
Defensive line
Three-time Pro Bowler Cameron Wake remains the anchor in the team's 4-3 front. The emergence of defensive end Olivier Vernon, however, was perhaps the most pleasant surprise in 2013. Tackle Jared Odrick will step in for Paul Soliai, who bolted to the Atlanta Falcons, and play next to Randy Starks in the middle. One player to watch is end Dion Jordan, who struggled as a rookie but could become a dynamic pass rusher after bulking up and learning the playbook.
Linebacker
The second line of the defense is mostly intact with one exception, as Koa Misi moves to middle linebacker while Dannell Ellerbe shifts to the outside. Misi wasn't particularly effective last season, registering 54 tackles and two sacks in 15 games. He'll need to step up in his new spot. Ellerbe, meanwhile, is a better fit on the strong side. Philip Wheeler returns to man the weak side.
Secondary
Brent Grimes was perhaps the best addition to the Dolphins last season. And with a new contract, he is expected to continue to be a formidable presence. If he can improve on his four interceptions in 2013, Grimes could establish himself as one of the best cornerbacks in the AFC. The two free agent additions — cornerback Cortland Finnegan and safety Louis Delmas — should help improve a secondary that ranked 16th in the NFL last year with 234.5 passing yards allowed a game.
Special teams
For the most part, Miami's special teams should remain in place. Kicker Caleb Sturgis was inconsistent (26-for-34 on field goal attempts) as a rookie but is expected to become more reliable in his second year. Brandon Fields will continue his duties as the punter, and Marcus Thigpen should contribute on punt and kickoff returns. He'll get competition from Landry.
Coaching
Philbin kept his job, but if there are continued problems in the locker room, he's likely to be gone. Lazor might be the team's most important addition. He has worked under a slew of the game's top coaches. Kevin Coyle is back to run the defense, and Darren Rizzi handles the special teams
