NASHVILLE, Tenn. -- Here are five observations from the Dolphins training camp:

	Sam Madison has 23 interceptions in five seasons in the NFL.

1. Sam Madison is one of the best cornerbacks in football. Teammate Patrick Surtain is making a bid to join him in the Pro Bowl. Surtain, one of the highest paid corners in the NFL like Madison, is looking like a Pro Bowler. Along with his incredible ability to cover, he remains physical at the line of scrimmage with receivers who have trouble getting off the line. His techniques have improved because he now focuses on watching the receiver and not worrying about covering every route. With Madison and Surtain one of the best one-two punches at corner, the Dolphins need to get improved play from last year's first-rounder Jamar Fletcher as the third corner.

2. Though there are worries about injuries that might have carried over from last year, the Dolphins offensive line looks much more physical and imposing. One of the biggest surprises is guard Jamie Nails, a former 380-pounder who came to camp weighing 335 pounds and has been dominating defenders. If veteran guard Leon Searcy can come off two years of injuries, the Dolphins will have a deep guard group that currently starts Mark Dixon and Todd Perry, but has some big backups who will help the running game. The problem is at left tackle. Brent Smith struggled in the scrimmage Saturday against Titans defensive end Jevon Kearse.

3. The defensive line was a highlight for the Dolphins in Saturday's scrimmage against the Titans. Recently acquired defensive end Jay Williams had two sacks. Defensive tackle Larry Chester had one. Defensive end Jason Taylor constantly applied pressure. The Dolphins backup defensive line, featuring veteran end Rob Burnett, overpowered the Titans backup offensive line during one stretch and sacked Neil O'Donnell four times in six plays.

4. Tight end Randy McMichael, a fourth-round choice, could end up starting. Jed Weaver is a solid tight end and is running with the first team for the moment and Alonzo Mayes is a talent who had to lose 40 pounds to report to camp at 260. But McMichael has the ability to get deep on a safety, which could propel him into a starting job. Turner's offense has always been good to tight ends.

5. Even though the Dolphins are exceptional at cornerback, don't forget the value of their safeties. Free safety Brock Marion helps out the corners because of his range of coverage and knowledge of the game. His value is underestimated in this secondary. Arturo Freeman takes over for departed Brian Walker and seems to work well with the rest of the secondary.

John Clayton is a senior NFL writer for ESPN.com.