All five starters return from last year, but the Dolphins were very busy in the offeason trying to add depth and competition up front.
Newcomers include tackles L.J. Shelton and Mike Pearson, guard Bennie Anderson and rookie guard/tackle Joe Toledo. While Toledo probably won't compete for a starting job in his first year, the other three will be in the mix.
Shelton looks like the front-runner to start at left tackle, but he could face a challenge from incumbent Damion McIntosh.
Pearson, for his part, could challenge incumbent Vernon Carey for the starting job at right tackle, where McIntosh could be a factor as well.
Anderson will be in the mix for the starting right guard job, for which he'll battle with former starting center Seth McKinney. McKinney switched spots this summer with Rex Hadnot, who joins Jeno James as the only almost-sure starters on the offensive line.
The only other starting job on offense that appears up for grabs is fullback, where free agent pick-up Fred Beasley figues to have the edge over returning starter Darian Barnes. While Barnes did a decent job last season and is a solid blocker, Beasley's experience and pass-catching ability could make the difference.
On defense, the most heated battle will be at outside linebacker, where Donnie Spragan will compete with free agent pick-ups Keith Newman and Sedrick Hodge for the chance to replace Junior Seau in the starting lineup.
Spragan's one year in Miami will help his cause, while Newman's pass-rushing ability might give him the job. Hodge appears the long shot in this battle.
In the secondary, training camp will decide who starts, but rookie Jason Allen (free safety) along with Will Allen (cornerback), Travis Daniels (cornerback) and free agent acquisition Renaldo Hill (strong safety) will go in as the front-runners to win the jobs.
The most important non-starting battle is for the No. 3 receiver role. Wes Welker handled that role late last season, but the Dolphins would prefer he concentrate on his return duties.
The thing is, there's no other veteran proven commodity on the roster, so the Dolphins will have to choose from among a group that includes former Minnesota draft pick Kelly Campbell and third-round pick Derek Hagan.