Cowboys position series: Defensive tackles

The seventh in ESPNDallas.com’s 10-part position series:

Roster locks: Jay Ratliff, Jason Hatcher, Sean Lissemore

On the bubble: Ben Bass, Nick Hayden

Long shots: Ikponmwosa Igbinosun, Jeris Pendleton, Jerome Long

Jailed: Josh Brent

What’s new? Ratliff’s 32-year-old body, which endured a plantar fascia problem, high ankle sprain and sports hernia as he missed 10 games in 2012, will face a lot fewer double-teams. Playing tackle in a 4-3 scheme certainly isn’t a finesse job, but it’s not as brutal a task as being an undersized 3-4 nose tackle, which Ratliff did with remarkable durability for five seasons before last year.

Hatcher has to learn a new position after spending his first seven seasons playing defensive end in a 3-4.

The Cowboys ignored the position in the draft despite Florida’s Sharrif Floyd, ranked fifth overall on their board, falling into their laps at No. 18. Jerry Jones valued the opinions of new defensive coordinator Monte Kiffin and defensive line coach Rod Marinelli -- who didn’t think Floyd was “quick-twitch” enough to excel in their scheme -- over those of the scouts.

In Marinelli, whose success as a defensive coordinator makes him highly overqualified for the job, the Cowboys can confidently say they have the best D-line coach in the business. He developed Warren Sapp and coached the Hall of Famer during his best seasons. He also developed former Texas running back Henry Melton, who was a fourth-round project, into a Pro Bowler in Chicago. Marinelli’s expertise in stunt games should help free up his rush men.

Camp competition: Bass and Hayden are either competing for one roster spot or trying to play well enough to convince the Cowboys to keep an extra DT.

Bass, an undrafted flier who didn’t play much at Texas A&M, earned a practice squad spot as a rookie, showed some promise after injuries led to a promotion and continued to progress during the offseason.

Hayden, 27, is a 6-foot-4, 300-pound run-stuffer who was a 10-game starter for Carolina in 2010 but was out of football last season. He might be useful as a spot 1-technique, a position that isn’t natural for either of the starters.

2013 hope: The best-case scenario is that Kiffin’s scheme and Marinelli’s coaching revitalize the career of Ratliff, a four-time Pro Bowler whose sack total dropped for the fifth consecutive year in 2012, bottoming out at zero. Jones, in particular, pumped this possibility up on a regular basis during the offseason.

Hatcher and Lissemore need to be sturdy enough to mask the fact that the Cowboys don’t have a 320-pound clogger.

Future forecast: Hatcher, whose three-year, $6 million second contract has been a bargain, is entering a contract year. Ratliff has collected most of the guaranteed money from the seven-year, $48.6 million deal he signed in 2011 and should be expendable if he has another down year.

Lissemore is locked up to a team-friendly, five-year, $7.2 million deal through 2016, and Bass has potential, but this position should be among the Cowboys’ biggest offseason needs.