Dolphins back-to-work FYI

Readiness factor: The Dolphins might be the most prepared team in the NFL based on offseason workouts. Because so many players make South Florida their year-round homes, getting them together wasn't difficult. The Dolphins gathered early and frequently during the lockout.

Biggest challenge: Miami must overcome multiple institutional issues that have placed key people on the hot seat. Head coach Tony Sparano is back for a fourth season after owner Stephen Ross publicly flirted with Jim Harbaugh, and the team's hopes appear to be pinned on unproven quarterback Chad Henne, likely an unproven-but-still-unnamed running back and new offensive coordinator Brian Daboll, who was less than inspiring with Cleveland.

Defense in focus: While the offense is in doubt, defensive coordinator Mike Nolan's group is in solid shape. The whole crew essentially is back, a young group that now has another year of experience. The Dolphins ranked sixth in total defense, seventh in run defense and eighth in pass defense. If you're looking for an area that must improve, then turnovers would be the place. Ball hawking is a core Nolan belief, but the Dolphins notched only 11 interceptions and recovered eight fumbles last season.

Key players without contracts for 2011: Running backs Ronnie Brown and Ricky Williams are the most prominent. Backup quarterback Tyler Thigpen also is on the list.