Our position-by-position analysis of the four teams in the NFC East continues with a look at the many changes along the Dallas Cowboys' offensive line.

Projected starters: LT Tyron Smith, LG Nate Livings, C Phil Costa, RG Mackenzy Bernadeau, RT Doug Free

Reserves: C Kevin Kowalski, G/C Bill Nagy, T Ronald Leary, T Jermey Parnell, G David Arkin

Potential strength: The tackles should be a strength. Smith, the 2011 first-round pick, was outstanding at right tackle as a rookie, and the Cowboys have no reason to doubt he can handle the move to the more important left side. They also believe the move back to right tackle could help Free, who struggled at times in his second year on the left. The NFC East features a lot of very good edge rushers, but the Cowboys believe they have the men on the outside of their offensive line to handle it. New offensive line coach Bill Callahan is also viewed by many as an upgrade whose presence should help the tackles and the rest of the offensive line perform better.

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Potential weakness: Center still stands out as a problem area. Costa was not very good last year, and there remains a chance he could be replaced by Bernadeau (though he's out for a couple of months following hip surgery) or Nagy. For it to be Nagy, he's going to have to show improved strength over last year. If he does, then from a technique standpoint he's a threat to start at center or either guard spot over the guys listed as projected starters there. Kowalski is also well regarded by the Dallas coaches and front office and could work his way into the mix if Costa does not show improvement.

Keep an eye on: The offseason competition at guard. The Cowboys signed free agents Bernadeau and Livings thinking they'd be starters, but neither is 100 percent guaranteed a starting spot. Nagy, Arkin and others loom as threats in what coach Jason Garrett has said many times will be a competition in the offseason and in training camp. Garrett's hope is that this competition brings the very best out of all of his players, thereby improving them all and giving him higher-quality choices from which to pick his starters when the time comes. We shall see. The interior of the line was a big problem for quarterback Tony Romo (not to mention the running game) in 2011, and it will need to show improvement if the Cowboys are to improve on their 8-8 record.