-- Clinton Portis looks every bit like the NFL's next great runner. Only 22, he has begun his pro career with consecutive 1,500-yard rushing seasons, and the Denver Broncos easily could have envisioned a return to the Super Bowl with Portis as their offensive centerpiece, their new Terrell Davis.

It seemed like such a tidy, perfect story line when the season ended.

But as the Broncos became the first NFL team to have veterans report to training camp by gathering here Tuesday, Portis was long gone, traded to the Washington Redskins in March for cornerback Champ Bailey and a draft pick in a rare swap of Pro Bowl players. The Broncos felt they could part with Portis because Bailey gives them the shut-down cornerback they have lacked for years and because officials did not want to deal with Portis's demands for a new contract.

And, besides, Coach Mike Shanahan always has been able to find The Next One.

From Davis to Olandis Gary to Mike Anderson to Portis, Shanahan has been able to find a tailback to plug into his system, grinding out yards behind a solid offensive line. In five seasons between 1998 and 2002, four Broncos tailbacks have rushed for more than 1,100 yards in a season. Now Shanahan will spend the coming weeks trying to find a replacement for Portis in an open competition among Quentin Griffin, Tatum Bell, Garrison Hearst, Anderson and perhaps others.

"You're talking about guys who haven't proven themselves yet," Shanahan said at the Broncos' training facility. "There are always question marks, but I feel very good about where we're at offensively. I think we'll be very good. . . . I think we have running backs who will fit into the system and do very well."

The pre-camp favorite is Griffin, a second-year pro who missed training camp last year because of a broken bone in his leg but had 136 rushing yards in a December game at Indianapolis when Portis was hurt. He was a fourth-round draft choice last year out of Oklahoma but is small for an every-down NFL tailback, at 5 feet 7, 195 pounds.

Bell, a rookie selected out of Oklahoma State with the second-round draft pick the Broncos obtained from the Redskins in the Portis trade, also has a chance to win the job, as does veteran Hearst, signed as a free agent after he was released by San Francisco. Anderson, Cecil Sapp and Ahmaad Galloway are the second-tier candidates. But Shanahan doesn't shy from underdogs. Davis and Anderson were sixth-round draft choices, and Gary was a fourth-round selection.

The Broncos have been successful with running backs in part because of the system used by Shanahan and in part because of their skilled offensive lines. But offensive line guru Alex Gibbs was hired in the offseason to be the Atlanta Falcons' offensive line coach, so Shanahan's task is tougher. He said he doesn't intend to use a time-sharing setup.

"I think everybody feels better with one guy in that role," Shanahan said. "Who that guy is going to be, I'm not really sure at this time. We've got a depth chart. I think everybody understands that you begin with a depth chart, but who wins that job going into the season, I don't know.

"When I first came here, nobody thought Terrell Davis was going to be the guy. Terrell Davis was a third- or fourth-team guy. But through the preseason games, we got a good feel that this guy might be special. We'll get a chance to evaluate these guys. I do think we have good depth there. I don't think our running backs will disappoint our fans."

Denver got Bailey and signed former Tampa Bay safety John Lynch as a free agent to upgrade a secondary that surrendered 377 passing yards and five touchdowns to Colts quarterback Peyton Manning in a 41-10 loss on Jan. 4 in an AFC first-round game. That left the Broncos without a postseason victory in five seasons. They're 0-2 in the playoffs since winning the second of two straight Super Bowls on Jan. 31, 1999, and the losses have come by a combined margin of 62-13. It's enough to perhaps taint Shanahan's genius label, but he said he's energized and optimistic for his 10th season as Denver's coach.

"It seems like the same to me -- the same pressure, the same expectations," he said. "Everybody says it changes as you get older. I don't think it does. I still look forward to the season and the competition. People ask, 'The expectations are pretty high, huh?' Yeah, that's why you play this game and that's why you coach it."

Four other teams -- the Falcons, Philadelphia Eagles, St. Louis Rams and Chicago Bears -- had their rookies report to camps Tuesday. The Broncos are the only club that also had its veterans report. Denver faces the Redskins on Aug. 9 in the Hall of Fame Game in Canton, Ohio.

Note: The Broncos released veteran linebacker John Mobley, who was advised by doctors to sit out this season after suffering a bruised spinal cord at Baltimore last October. Mobley, 30, failed his physical, but Shanahan left open the possibility he could return if cleared to resume his career.

"If in six months or a year he feels like he's ready to go, we'll assess it then," Shanahan said. "But right now, he's failed his physical and only time will tell. . . . It does not mean we do not want John Mobley on our football team.''

Quentin Griffin, who ran well in a backup role for Clinton Portis, gets the nod in Denver, which turned out four 1,100-yard runners between 1998 and 2002.