However, they don't like each other enough to simply give up their carries to the other.

"Competition is good," said Mack.

It will be for the running backs, whose battle for the starting role should be one of the most intriguing competitions in the Utes' fall camp.

Utah's camp started Monday with 104 players in attendance, one short of the maximum allowed. The final slot is being saved for receiver Aiona Key, a junior college transfer who should be in camp by the end of the week.

Utah coach Kyle Whittingham said he saw a lot of positives from his team in its first workout for the 2008 season, which kicks off at Michigan on Aug. 30.

By then, maybe the Utes will have a starting running back - or not. Asiata and Mack both worked out with the starters Monday. Whittingham referred to the players as "1 and 1-A" and said the competition between the backs should be nothing but a positive for the Utes. He wasn't concerned about having a designated starting back in time for the season opener.

"It's a great problem to have and there is a good chance we'll see both in the backfield a lot," he said. "There are plenty of reps for both those guys to go around."

A perfect situation to him would be similar to 2004, when the Utes used Marty Johnson (165 carries, 802 yards, 14 touchdowns) and Quinton Ganther (109 carries, 654 yards, two touchdowns) as a combo to wear down defenses.

Sometimes splitting duties like that between players can be a distraction as each tries to establish himself as the main guy. For now, both Asiata and Mack are buying into the possibility of such a shared system.

"I just want us to win," Mack said. "As long as we do better as a team, I don't care what I do individually."

Mack enters the season as the proven back, a position he never thought he'd be in a year ago when he was tabbed to be redshirted while the much-hyped JC transfer Asiata was designated as the Utes' starter.

Everything changed for the two when Asiata broke his leg after just four carries in the season-opening loss at Oregon State.

Mack not only won the starting job, but finished with 1,204 yards, the third-highest total season total by a Ute. While he no longer feels like an underdog who must prove he deserves carries, he knows he can't coast in fall camp either, especially with Asiata healthy again.

"I've never been in this situation before, and it feels good, going into camp as a starter," Mack said. "But I have a lot of things I want to improve on. I know I can do better."

For his part, Asiata is eager to show he deserves all the hype he has received since he earned junior college All-America honors at Snow College.

He had surgery to repair his broken leg shortly after the injury and was held out of contact in spring ball. There will be no such restraints as he competes with Mack for carries.

"As long as I participate, I'll be happy," he said. "We both want to win."

Notes: Quarterback Brian Johnson and receiver Brent Casteel both looked good in Monday's workout and showed no ill effects of the injuries from 2007.

Johnson overthrew Casteel on one pass, but took it as a good sign.

"I couldn't overthrow anyone to save my life last season," he said. "It's a lot easier to take some off the passes than put some on."

Johnson said the team's high expectations for the season led to a focused practice, something he believes will be a characteristic of all the Utes' practices this season.

"This team is tired of underachieving," he said. "We are tired of seven-, eight-, nine-win seasons. We have the talent to do better than that and we realize it's up to us."

* Sophomore Neli A'asa has been moved from offensive line to tight end. . . . JC signee tight end Dudley LaPorte is not eligible this fall, but plans to enroll in January. . . . Redshirt freshman Jordan Nelson, an offensive lineman, is out indefinitely with a broken foot. . . . Freshmen Sam Brenner and Zach Davila will enroll in the winter instead of the fall because of injuries. . . . Utah's first day in pads will be Friday, and the first of six two-a-days is Saturday.

lwodraska@sltrib.com

Ute running backs

DARRELL MACK

Spring Valley, Calif.

6-0, 220 pounds, Sr.

Claim to fame: Became the school's ninth 1,000-yard rusher in 2007

Fall camp question: Can he duplicate his performance in 2008, or will he go back to being a backup?

MATT ASIATA

West Valley City

5-11, 230 pounds, Jr.

Claim to fame: Led the Western States football league in rushing with 1,365 yards and 15 touchdowns in 2006

Fall camp question: Known as a hard-hitting back, will Asiata trust his surgically repaired leg to go all out in games?