A big key for the Dolphins on the offensive line is right guard Donald Thomas

Jake Long and Jake Grove in particular seemed to have their problems, but both are very talented players that should get things straightened out.A big key for the Dolphins on the offensive line is right guard Donald Thomas. He was a monster at times during the 2009 preseason, and the team really struggled to fill the right guard spot all of 2008 when Thomas was lost in the season opener. If he can perform nearly as well as most seem to think he can, he'll be a huge asset up front.The Dolphins' line isn't quite "there yet," but it is solid and I do expect they'll get better as they play together more and the season progresses. I think there's enough young talent in the unit to eventually be one of the best lines in all of football.Grade: BDefensive LineI've consistently said that defensive end is possibly the Dolphins' deepest position, and I certainly still believe it. Kendall Langford was extremely impressive as a rookie, while Randy Starks and Phillip Merling both came along quite nicely as well.

Tony McDaniel and Lionel Dotson both look like solid backup material and could be worthy of spots in the line rotation before season's end.Nose tackle is a bit of a long-term concern because of Jason Ferguson's age, but that's not an issue in 2009 because the guy can still clog up the middle as well as most. He's a good anchor when he's in there, and Paul Soliai is a quality backup nose tackle to have despite his disappointments thus far.Grade: A-LinebackerOutsiders seem to think Jason Taylor is washed up and over-the-hill because of an injury-plagued 2008 in Washington, but everything we've seen since his return to Miami has been positive. The guy's leadership cannot be overstated, but that's secondary to his play on the field, which is still excellent. Not only is Taylor still a quality pass-rusher, but he's also better against the run that people give him credit for.Joey Porter should continue to thrive as a pass-rusher in Miami, especially now playing opposite Taylor.

One thing he must get better at is his run defense, which was nothing short of horrendous in 2008. Matt Roth, whose strange preseason absence has been well-documented, was Miami's best run-stopping outside linebacker, so it's time for Porter to step up.The Dolphins are pretty solid up the middle with Channing Crowder and Akin Ayodele, though both miss a few too many tackles for my liking and I'd prefer to see them clamp down on that sort of thing. The defensive line is doing its job in occupying the blockers now it's time for Crowder and Ayodele to do their part.Depth across the linebacker positions is solid, and at times, quite intriguing. Charlie Anderson has already established himself as a good situational rusher, while CFL import Cameron Wake could be a real sleeper prospect for the Dolphins. Reggie Torbor, while overpaid, is a solid third inside linebacker, while Erik Walden and Quentin Moses are both decent, young backups outside.Grade: BCornerbackWill Allen is a better corner than most around the league give him credit for and is a viable No 1 option. He should continue to play at a high level for the Dolphins and is an excellent veteran under which the Dolphins' rookies can learn.Speaking of those rookies, Sean Smith and Vontae Davis have big shoes to fill in trying to replace departed free agent Andre' Goodman.