CHAPEL HILL - Had North Carolina switched Greg Little from wideout to tailback earlier last season, coach Butch Davis said recently, the Tar Heels might have had a better shot of making a bowl.

So now that the sophomore from Durham is entrenched as the top running back in training camp, UNC's coaches are concentrating on finding Nos. 2, 3 and 4 -- because they don't want to make the same mistake again.

"There is no way in the world we will make it through this season with just the significant contributions by one running back," Davis said Friday, roughly two hours before the Tar Heels took the field for their first practice of the 2008 season. "We have to have Ryan Houston play well. We've got to have Devon Ramsay. We've got to have Jamal Womble."

Indeed, Davis said one of the biggest keys to turning last year's 4-8 finish into Carolina's first winning season since 2001 is building depth in the backfield -- and beyond.

The coaches need to choose a backup quarterback for T.J. Yates, who displayed familiar zip on his throws despite offseason shoulder surgery. They would like to be able to rotate eight to 10 defensive linemen each game. They want to have deep cushions of personnel at the corners, at linebacker, and even at wide receiver -- where the Tar Heels return three of the best pass catchers in the league.

But they also need to build a solid rotation at tailback, where the Tar Heels played "ball-carrier-by-committee" last season before they, as Davis put it, "found out that maybe the best running back that we had on the football team was playing wide receiver."

Little went on to rush for 243 yards in the final two games, giving fans reason to hope for more stability in the backfield. And although he is still learning the position, Little wants to add to those numbers -- in a big way.

"I know I want to be a 1,000-yard back; I want to be the best running back in the nation, and that's what I'm setting my sights for," he said.

Any shot at the latter will take time. While the coaches are excited about his potential, "by no stretch of the imagination is he a finished, refined, polished running back," Davis said. "He's got a lot to learn."

But after working on his speed and regaining the weight he lost after walking on to the Tar Heels basketball team (he's back to 225 pounds), becoming UNC's first 1,000-yard rusher since Jonathan Linton in 1997 isn't out of the realm of possibility -- with plenty of sweat and some help.

As much as Little would like to grab all the carries, there are several options to give him a breather.

Matthews' Houston, a bruiser who rushed for 145 yards last season, came out of spring practice as No. 2 on the depth chart. Running backs coach Ken Browning has been impressed by both Houston's weight loss -- he is listed at 250 and Browning estimates he's lost 25 pounds -- and work ethic. Veterans Bobby Rome and Anthony Elzy are slotted as fullbacks. In addition, Browning also wants to take good looks at Ramsay, a redshirt freshman, and Womble, a true freshman.

"We have a lot of competition, and that's a good thing," Browning said.

And while the coaching staff builds depth, Little will work to refine his skills as the feature back in UNC's offense, an offense that has struggled to run the ball effectively on a consistent basis for years.

"He's got two of the qualities you have to have to be a great running back ... beginning with toughness and competitiveness," Browning said. "He will keep getting better as a practice player; and as he keeps raising his expectations ... he'll figure out, 'I have to work harder on this, I have to spend more time on this.' Because he's got so much pride, he's going to want to be good."

BRIEFLY: Freshman linebacker Kevin Reddick and junior college transfer Joseph Townsend, a defensive end, did not report for practice because of academic issues. Reddick, from New Bern, attended summer school classes but has not been cleared by the NCAA Clearinghouse, Davis said.

"Hopefully it will resolve itself in the very near future," he added.

Townsend, who played at Los Altos Hills (Calif.) Community College, has to take care of some academic work before he can enroll in the fall, a team spokesman said.