Let's continue our breakdown by position of the Pittsburgh Steelers roster with a look at the situation at cornerback.

As you're likely well aware, the Steelers pass defense has improved dramatically in the first two years of the Mike Tomlin era. In 2006, the Steelers failed to even make the playoffs a year after winning Super Bowl XL. Part of the reason was a porous pass defense that yielded 212 yards per game through the air (20th in NFL). In Coach Tomlin's first year, that number fell to 176.5 yards per game (3rd) and in 2008 the Steelers led the league in pass defense after allowing an amazingly modest 156.9 passing yards per game.

There are lots of factors in play when assessing a team's pass defense. It helps when you have a front seven that creates tremendous pass pressure for example. It helps to be involved in close games (or even trail frequently) so that teams are not taking to the air furiously trying to catch up. It also helps to have a super-human athlete like Troy Polamalu patrolling the field and a disciplined but big hitting strong safety in Ryan Clark enforcing the middle of the field.

All that said, defending the pass in the National Football League requires talented athletes and savvy, high-IQ guys at the cornerback position. And it requires having more than just one horse in the stable.

A Tour Through The Depth Chart

Locks: Ike Taylor, Deshea Townsend, William Gay

The Steelers will once again rely on Ike Taylor to be the foundation of their cornerback unit. Over the past two seasons, Taylor has a nearly impeccable track record shutting down some of the NFL's best wide receivers. Sure, he's had moments that have forced us fans to consider if Taylor is truly one of the game's elite lock-down corners. But the proof is more or less in the pudding with him. He's been very good, if not spectacular, for quite some time now.

As for Deshea, there's cause for concern that this may finally be the year that he slows down and is unable to play at such a high level as his career approaches twilight. Maybe not though. Townsend is, after all, one of the more intelligent and cagey players on all the roster - if not the most. In an ideal situation, Townsend will be able to continue doing what he does best - making plays from his nickelback position by placing himself in the right place at the right time. A less ideal development would be if he had to re-assume some of the #2 cornerback duties due to William Gay struggling in his first full year as a starter. Townsend will be a free agent in 2010 and it doesn't appear that re-upping him is in the cards, at least for the time being. He may very well be re-signed somewhere down the road, but my guess is that the organization will first assess what they have in Gay and rookies Keenan Lewis and Joe Burnett before making any sort of determination about whether or not to keep Townsend in Pittsburgh beyond the 2009 season.

Back to William Gay. For me, his development and play in 2009 will be one of the more important stories of the year for the reigning Super Bowl champions. The third-year corner out of Louisville shined both on special teams and on defense during his first two seasons in the league, particularly last year when Bryant McFadden broke his arm. Gay benefitted tremendously from out-of-this-world play by safety Troy Polamalu though. What might happen if the Steelers were to lose one of their top-notch pass rushers or their All World safety? Would guys like Deshea and Gay look less impressive than they otherwise might when they're being safe guarded by some of the best table setters in football? Who knows but as we saw in the Super Bowl last year and throughout various points in the 2007 season, the Steelers defense walks a fine line between being an excellent pass defense and one that is good but also vulnerable.

After those three guys, the depth chart opens up a bit in the Steelers secondary. Here are the names of the other cornerbacks competing for roster spots.

Anthony Madison, Keenan Lewis, Joe Burnett, Keiwan Ratliff, Roy Lewis

Of these players, I feel most comfortable about the chances of Anthony Madison to make the 53-man roster at the outset of the season. Why? Well, for starters, he was the team's leading special teams tackler last year. We all know Tomlin isn't about to go about de-emphasizing special teams so expect Madison to once again anchor Pittsburgh's coverage units. That means he'll be a reserve cornerback as well, something he's proven capable of doing during his tenure in Pittsburgh. He's also in the last year of his contract and would be worth utilizing before deciding what to do with him in an uncapped 2010 season. He provides tremendous value and is a proven commodity at this point in his career.

The next most likely guy to make the 53-man roster, in my opinion, is Joe Burnett, the team's 5th round selection from Central Florida. Burnett had 16 career interceptions in college as a cornerback but largely made a name for himself as a return specialist. In fact, he was a 1st team All American last year for his accomplishments returning punts and kicks. The kid seems to just have a sure set of hands as well as natural instincts in open space after fielding the ball. I'd imagine that he will return punts this year for Pittsburgh, as well as perhaps assume some of the nickel and dime duties that William Gay handled last year. I'm as excited about Burnett as I am about any Steelers draft pick this year.

Don't forget about the other cornerback the Steelers drafted this past April - Keenan Lewis. Early reports from OTAs about Lewis' progress seem promising. I think he's probably a bit too raw to be trusted too much on this top-ranked defense in 2009, but I am also quite high on the former Oregon State product. He's big and rangy at 6'1" and is more physical and willing to get dirty, so to speak, than people
give him credit for. But he'll have to prove he can play against the run and tackle in open space before seeing the field regularly, I'd imagine. My guess is Lewis will either be on the practice squad or dress but not be a part of the 53-man active roster for much of the year. That said, if Burnett or fellow rookie Mike Wallace do not prove to be up to the task of being on the roster for special teams purposes, than Lewis may very well find himself as the team's 4th or 5th cornerback.

Providing insurance and experience are Keiwan Ratliff. Ratliff was acquired during free agency from the Indianapolis Colts. He was signed to an inexpensive one-year deal. The 28-year old probably is better than Madison as a cover corner, but he could find himself the odd man out if Pittsburgh's youth movement wins out during what promises to be a competitive training camp in Latrobe.

Finally, 2nd-year undrafted free agent Roy Lewis is worth keeping an eye on because of the potential positional flexibility he has shown to be either a corner or a cover. If he could provide relief in the event of injuries at both positions, that may make him more likely to win a precious roster spot than a guy like Ratliff or perhaps even one or both of the two rookies discuss previously. This may not be the year for Lewis to get an opportunity to break through - 2010 might be more likely when Gay, Townsend, Madison and Ratliff are all set to be free agents. We'll just have to wait until the pads go on to see, though.

There you have it. There should be quite a bit of healthy but intense competition at camp this summer at the cornerback position. Thoughts?