Dolphins coach Joe Philbin outlines the improves he needs to see from Ryan Tannehill

The Miami Dolphins filled the team's most glaring holes on offense in free agency, adding one of the NFL's most dynamic playmakers in Mike Wallace, and a proven, accomplished seam threat tight end in Dustin Keller.

But there are still areas of concern General Manager Jeff Ireland must address before the 2013 version of the Dolphins begin training camp in late July.

Here is a breakdown of each offensive unit, and a look at what could be next for the Dolphins as free agency continues to trickle along, and teams turn their attention toward next month's NFL draft.

OFFENSE (31 players presently signed by the Dolphins)

QB: Ryan Tannehill, Matt Moore, Pat Devlin

Breakdown: Tannehill had a respectable season as a rookie starter, but still has a long journey ahead to catch some of his peers (Andrew Luck, Robert Griffin III, Russell Wilson, Nick Foles, Colin Kaepernick, Cam Newton, Andy Dalton, Jake Locker and Christian Ponder). Moore signed a two-year deal to remain Tannehill's backup, and Devlin is entering year three as a developmental project.

What now: Cross your fingers and hope Tannehill produces a winning record, and an 85-plus passer rating in 2013 because if he doesn't we could be looking at yet another regime change. The Dolphins offense possesses better weapons now, but Tannehill needs his offensive line fortified to flourish. The Dolphins might add another young quarterback to push Devlin for the No. 3 spot.

RB: Lamar Miller, Daniel Thomas, Marcus Thigpen, Jonas Gray

FB: Jorvorskie Lane, Charles Clay (H-back)

Breakdown: The Dolphins let Reggie Bush sign with Detroit because they are excited about Lamar Miller's future based on his 4.9 yards per carry average, and upside. Miami is concerned about Thomas' durability, and his ability to be the big, physical goal line runner the offense needs. Thigpen is a pass catching option who is dangerous as a slot receiver, and the Dolphins invested a full season in Gray, allowing him to recover from a torn ACL he suffered in November at Notre Dame. At this point what Gray brings to the table is a mystery. Lane, an overweight fullback, wore down at the end of the season, so it would be ideal for the Dolphins to add competition at the position, especially if they view Clay as more of a tight end than lead blocker.

What now: While tailback happens to be one of Miami's deepest positions, don't be surprised if the Dolphins add another big, physical back in the Peyton Hillis mold to serve as a short yardage runner. There are a few in the draft - Wisconsin's Montee Ball and Michigan State's LeVeon Bell - who would provide Miller and Thomas some much needed competition. If the Dolphins add a veteran tailback it will be on a minimum contract.

TE: Dustin Keller, Michael Egnew, Kyle Miller

Breakdown: The Dolphins swapped out Anthony Fasano, a pass blocking red zone threat, for Keller, a rocked up receiver who is a seam threat. If Keller's healthy he should challenge linebackers and occupy a safety on a regular basis. But Keller is only signed for one season, which means he's on a tryout with the Dolphins. Egnew, a third-round pick in 2012, isn't guaranteed a roster spot. He needs to get stronger, tougher, and improve his play speed to make the 53-man roster again in 2013. Miller has special teams value, but he's a bit of a mystery at this point.

What now: The Dolphins need a tight end that can adequately pass protect considering Keller, Clay and Egnew are all weak in that aspect of a tight end's duties. Miami might address the position in the draft, or possibly sign one in free agency. This draft class features five promising tight ends - Notre Dame's Tyler Eifert, Stanford's Zach Ertz, Florida's Jordan Reed, San Diego State's Gavin Escobar and Cincinnati's Travis Kelce - who will be taken in the first three rounds. After that group the pressure is off, but some decent projects (Rice's Vance McDonald, San Jose State's Ryan Otten and Stanford's Levine Toilolo) will be available.

WR (flanker): Mike Wallace, Davone Bess, Armon Binns, Brian Tyms

WR (split end): Brian Hartline, Brandon Gibson, Rishard Matthews, Jeff Fuller

Breakdown: The Dolphins were aggressive upgrading the weakest unit on the team last year, adding Wallace and Gibson to a unit which scored just three touchdowns in 2012. Wallace is the type of dynamic playmaker who stretches the field for everyone because his speed occupies a safety on every play. Gibson, who contributed 51 catches for 691 yards and five touchdowns last season with the Rams, checks in as ProFootballFocus.com's 39th best receiver in 2012. Right ahead of him is Hartline (No. 37) and Bess (No. 38) when it comes to production per snap. That means Miami now has Wallace and three No. 2 receivers on the roster. Behind the top four receivers are Binns, Matthews, Tyms and Fuller, who are four young receivers worthy of a continued investment.

What now: Because Bess is entering the final year of his contract, which will pay him $2.633 million in base salary and has a cap figure of $3.433 million, the Dolphins could shop the slot receiver before, during, or after the draft. However, anything short of a fifth-round pick for Bess wouldn't provide equal value considering this former Hawaii standout is viewed in NFL circles as one of the league's best spot receivers. The Dolphins typically carry five receivers on the 53-man roster and an additional two on the practice squad. So it appears this unit is pretty full, therefore not a priority in the draft unless Bess is moved.

LT: Jonathan Martin, Jeff Adams

LG: Richie Incognito, Chandler Burden

C: Mike Pouncey, Josh Samuda

RG: John Jerry, Lance Louis

RT: Nate Garner, Will Yeatman, Andrew McDonald

Breakdown: The Dolphins allowed Jake Long to sign with the Rams because they weren't willing to guarantee $20 million to an offensive tackle who has struggled to stay healthy the past three seasons. Martin replaced Long for the final five games of the 2012 season and played left tackle better than he did right tackle. It is likely that is where Martin, the team's second-round pick in 2012, will reside moving forward unless Miami's lucky enough to get one of this draft's top offensive tackles - Texas A&M's Luke Joeckel, Central Michigan's Eric Fisher and Oklahoma's Lane Johnson - which is unlikely considering they should all be gone by the first 10 selects. Re-signing Garner, who was solid as Miami's starting right tackle till the season finale, provides some flexibility considering he's been decent in stints as a starting guard or tackle. The Dolphins need to get more athletic at guard and signing Louis helps in that regard. But he's recovering from an ACL injury he suffered in November and might not be ready to challenge for a starting spot till August or September. Moving Jerry to offensive tackle is an option, but one the Dolphins don't seem to be in a hurry to do. Every player on the offensive line but Incognito, Pouncey and Louis should be viewed as projects because they either don't fit the body type and athletic mold Philbin wants, or haven't proven themselves enough on this level.

What's next: The Dolphins need to find more offensive linemen who fit the athletic mold Miami needs for its zone blocking scheme. That means they need to target offensive guards and tackles with good feet and the skills to make second-level blocks. Eric Winston, a free agent, has been a solid NFL starter for seven seasons, and he spent six of those years playing in a zone blocking scheme. However, the former University of Miami standout turns 30 this season and is viewed as more of a stopgap than long-term solution. Signing him remains a possibility, but it appears both sides are weighing their options. It is possible the Dolphins could target offensive tackles and guards early in the 2013 draft to fortify the right side of the offensive line. Miami should be in position to pick two of the draft's top talents - Alabama offensive guard Chance Warmack and North Carolina's Jonathan Cooper - with the No. 12 pick, but would likely have to move up to get a shot at Fisher or Johnson.

G.G.G.