IRVING, Texas -- Offensively, the Dallas Cowboys should be among the NFL's best in 2015, even without DeMarco Murray.

That statement is not meant as a slap at what Murray did in 2014 with his 1,845 yards rushing and 13 touchdowns. It's not to say the Cowboys can just plug in any running back and put up big numbers.

The statement is true because of the talent that remains.

Depending on who's doing the measuring, Tony Romo is a top 6-10 quarterback in the NFL. Dez Bryant is in the top handful of wide receivers. Jason Witten remains one of the best tight ends. The offensive line is the envy of just about every team in the league with three Pro Bowlers in Tyron Smith, Travis Frederick and Zack Martin.

And the Cowboys have role players that can produce, such as Terrance Williams, Cole Beasley and Gavin Escobar.

While staying injury free is the most important goal of training camp, what will make for a successful camp offensively?

Here are three keys:

Running from within: At one point a lot of people assumed Adrian Peterson would be a Cowboy. That didn't happen. At different points, people thought the Cowboys would take a running back in the first round -- or any round. That didn't happen either. At every stop along the way they have said they like their running backs: Joseph Randle, Darren McFadden and Lance Dunbar. Not many people have truly believed them because none of those backs has a track record to show they can come close to doing what Murray did. The Cowboys won't ask their runner to put up Murray’s stats from 2014, but they need one of them to take the job this summer. The Cowboys can’t go into the regular season hoping their 1,000-yard rusher is on the roster. They have to know they have a 1,000-yard rusher when training camp ends.

The Romo plan: Last summer Romo did not practice more than two straight days as he looked to preserve his surgically-repaired back. It took some time to find the right balance in the regular season to find a plan that worked for Romo, and resting and rehabbing on Wednesdays helped the quarterback have his best season. Romo did everything during the offseason program, not missing a day. But that doesn't mean he will get on some sort of Cal Ripken streak in Oxnard. As much as the Cowboys want Romo to get all the work, they still need to avoid overworking him. The goal is for Romo to be ready Sept. 13 against the New York Giants and beyond, not for an Aug. 21 practice.

Settle the line: The Cowboys know four of their five starters along the offensive line -- Smith, Frederick, Martin and Doug Free. The left guard spot will be a competition between Ronald Leary, who has started 31 of the last 32 games there, and rookie La'el Collins, who the Cowboys signed as an undrafted free agent to a fully guaranteed contract. As much as we hear Garrett talk about process we hear offensive linemen and coaches talk about the importance of cohesion up front. By the time the Cowboys get to their third preseason game, they need to settle the debate and have their five guys in place.