IRVING, Texas -- Nobody had a better view of DeMarco Murray's season last year than Dallas Cowboys running backs coach Gary Brown.

Murray set Cowboys records in yards (1,845), carries (392) and 100-yard games (12) in 2014. He set an NFL record with eight straight 100-yard games to open the season. By the end of the year Murray was named to the Pro Bowl and was the league's offensive Player of the Year.

Despite all of that, the Cowboys did not come close to matching the offer Murray received as a free agent to join the Philadelphia Eagles.

Brown's job this year will be a little harder.

"Looking at the type of guy DeMarco is, the way he works and things of that nature, I wasn't surprised about what he did," Brown said. "The yards were extraordinary, but I knew he was going to come out and work hard. We've just got to find a guy, or three guys that come in, or four guys, who come in and do what DeMarco did. Hopefully those guys are up for the challenge."

Those guys are Darren McFadden, Joseph Randle, Lance Dunbar and Ryan Williams. Brown isn't looking for one of them to do what Murray did.

"We're trying to replace all those yards, but if we have to do it with two guys, three guys, four guys, whatever it takes to help us win, we'll do that."

While the Cowboys have not loaded up at running back -- they didn't take one in the draft and Adrian Peterson isn't walking through that door -- they have loaded up on the offensive line. La'el Collins was added to a group that had three Pro Bowlers last year in Tyron Smith, Travis Frederick and Zack Martin.

But Brown subscribes to the same theory as head coach Jason Garrett: the runner matters.

"It makes our job easier, but what I've come to realize is that it's just not the offensive line," Brown said. "The back [has] got to go out and run. For people to say that you can just plug anybody in, it's kind of disrespectful to the guys that are running. You got to give them credit too. Obviously our offensive line is great, but you got to give some credit to the runners as well."

McFadden has the best pedigree, having been a former first-round pick and one 1,000-yard season. But he has not averaged better than 3.4 yards per carry since 2011.

"I just admired him from afar, watching him on tape," Brown said of McFadden. "I think he's big, strong, incredibly fast, tough guy. He's buying into our system. He wants to be here. He's doing everything I ask him to do. I'm looking forward to seeing him in pads."

Randle showed flashes last year he can fit in the system but he has had off-field issues that have not pleased the front office or coaches.

"I think Joe really has to make sure he takes care of everything on and off the field," Brown said. "We want to trust Joe. We like Joe, but we want to make sure he's going to be with us at all times. I think he's maturing up and he's getting better and he understands the opportunity he has in front of him and I think he'll take full advantage."

Dunbar is more of a situational running back, but he was not given much work last year mostly because of how productive Murray was. It didn't make sense to take him off the field.

"I think he's a hell of a football player, we've got to try and get him more involved," Brown said. "And I think coach Linehan is going to do a great job doing that."

Williams spent last year on the practice squad after a productive preseason.

"What we like about Ryan is his ability to make people miss, his short area quickness, his veteran ability to go out and do things and make things happen," Brown said.