The Miami Dolphins wrapped up training camp at team headquarters in Davie on Thursday morning.

There is still much about this season’s team that is yet to be determined and the final three games of the preseason should help shed more light on what kind of club head coach Joe Philbin has in year two on the job.

Everything we saw from the Dolphins in training camp is certainly subject to change, but here are five things we either found out or had confirmed about them over the past three and a half weeks.

1. Secondary is much improved

Even with a sidelined second-round pick in Jamar Taylor for the majority of camp, the Dolphins’ new-look secondary has been the team’s most-improved unit.

Former Atlanta Falcons cornerback Brent Grimes hasn’t really showcased the ball-hawking ability that made him a Pro Bowler in 2010, but that’s because Miami’s quarterbacks shy away from throwing in his direction. Grimes’ coverage has been lockdown in camp, which has prompted some to speculate he could be the team’s top offseason acquisition.

Opposite Grimes, Dimitri Patterson and Richard Marshall are still competing for a starting spot. Both have played much better than expected, though, and have gone from potential cuts to likely locks.

Third-round pick Will Davis has been the biggest surprise from the group. The rookie out of Nevada has been a pure ball-hawk, picking off more passes than he has fingers in practice and getting his hands on an interception last Friday night in Jacksonville. He still gets beat from time to time in coverage, but he’s positioning himself for playing time this season on a defense that needs to force more turnovers.

The Dolphins have come a long way from starting Jimmy Wilson and Nolan Carroll at corner in 2012.

Add one of the league’s best safeties in Reshad Jones along with his reliable sidekick Chris Clemons into the mix and the Dolphins should drastically improve against the pass after finishing 27th last season.

2. Offensive line remains work in progress

The Dolphins’ front office has invested more in the team’s offensive line than perhaps any other unit over the past five or six years. They haven’t had much return on that investment, however, as the line continues to struggle this preseason.

Letting former first-overall pick Jake Long sign with the Rams and entrusting Jonathan Martin with protecting Ryan Tannehill’s blindside is the decision that gets all of the headlines and criticism. But the Dolphins’ right guard spot has been nearly as worrisome.

Ever since John Jerry — a replaceable starter as is — had his left knee scoped, the Dolphins have had a difficult time finding an adequate replacement. Josh Samuda, who will get the nod on Saturday night in Houston, gave up a sack and several pressures against the Jaguars in preseason game number two.

Tannehill’s interior protection should improve when Jerry returns, as the near 350-pound guard has always been decent in pass pro. But depth along the offensive line remains a major concern.

3. Cameron Wake finally has help

The Dolphins have employed several solid defensive players over the past few seasons, but they’ve been a one-man show in the pass-rush department.

Cameron Wake — fresh off of a 15.0 sack campaign — has showed no signs of slowing down at 31 years of age, but Miami needs another rusher to alleviate some of the double teams he consistently receives. Or two, which the Dolphins may have in Oliver Vernon and Dion Jordan.

Vernon, a third-round pick in 2012, has impressed in practice and has earned the starting right defensive end spot for the time being. He looks to be a more polished pass rusher in year two, but it’s yet to be determined if Vernon is that improved or the guy he’s facing in practice — Jonathan Martin — is that bad.

Dion Jordan, meanwhile, continues to deal with the injured shoulder he had operated on during the offseason, but has flashed the explosiveness as a pass rusher that made him the top defensive player taken in April’s draft.

Expect defensive coordinator Kevin Coyle to get creative in how he utilizes Jordan this season. But regardless of how he does, Jordan makes the Dolphins’ defense a more athletic unit and gives opposing offenses another player to potentially double team in pass pro.

If the rookie can stay healthy and Vernon’s growth proves valid, it’s not unfathomable to think the Dolphins could make a push to lead the league in sacks this season.

4. Ryan Tannehill is still developing

This is not to say Ryan Tannehill can’t go on to have a fantastic season as a second-year starter. This is not to say I don’t expect him to, either. But it’s clear that Tannehill still has a few areas where needs to improve before ever emerging as one of the league’s elite quarterbacks.

I don’t think he necessarily has to become elite for the Dolphins to win this season, especially when he has capable playmakers around him and a potentially dominant defense on the other side of the ball. But Tannehill taking the next step as a quarterback would likely ensure a successful season.

So, what has to happen for him to do so?

We need to see Tannehill make quicker reads and to be aggressive about pulling the trigger when he has an open receiver. There have been times during the first two preseason games — albeit in limited action — when Tannehill missed open receivers or hesitated instead of making the throw immediately when he saw one.

He needs to have more confidence and poise in the pocket. In the Jacksonville game, in particular, Tannehill bailed on the pocket a few times prematurely, which limited his ability to set his feet and deliver a strike down the field.

We also need to see more consistent accuracy from Tannehill. He’s been off at times in practice this year and during the first two exhibitions. But we know Tannehill has the ability to make every NFL throw and we’ve seen him drop dimes with perfect placement in the past.

Personally, I think Tannehill just needs to get some momentum going and the confidence, the decisiveness will come. And that may be on the verge of happening for him after following up a touchdown drive in Jacksonville with an outstanding final week of training camp. Performing well in Houston would confirm that suspicion.

5. 2013 Dolphins > 2012 Dolphins — but will it be enough?

What’s clear about the 2013 Miami Dolphins? They’re a much more talented team than they were a year ago. And there’s really no debating that.

Tannehill is more experienced and actually has a capable set of pass catchers at his disposal after not having a legitimate seam-stretching tight end or a deep threat at receiver as a rookie.

Enter Dustin Keller and Mike Wallace. Both will open up the offense for Tannehill and the Dolphins’ running game, which dealt with far too many eight-man fronts in 2012.

Improvement could be even more drastic on defense, where the Dolphins are faster, more attacking at linebacker, deeper in the secondary and now possess more than one legitimate pass-rushing threat.

After just being above average against the run and stingy in the red zone in 2012, there’s really nothing stopping the Dolphins from fielding a complete defense in 2013 that effectively defends the run and the pass, pressures the quarterback and forces turnovers.

But will all of this improvement be enough? Enough to meet expectations of a hungry fan base? Enough to survive a brutal opening five-game schedule? Enough to make the playoffs in a division that has been dominated by the New England Patriots for over a decade?

It better be.