Broncos coach Josh McDaniels

After watching the backup running backs to Knowshon Moreno and Correll Buckhalter the past two days, one question repeatedly comes up at Dove Valley: When will Moreno and Buckhalter return?

Kolby Smith and Lance Ball have done a nice job under the circumstances. It's just that Smith was a backup for the lowly Kansas City Chiefs the past three years, and Ball has been with four teams and played one game the previous two years.

"Up and down," Broncos coach Josh McDaniels said when asked Tuesday about the play of Smith and Ball. "There's some good, and then there's some learning experiences that they're going through."

Neither Moreno nor Buckhalter made it past the first training camp Knowshon Moreno practice Sunday. Moreno suffered a severe right hamstring injury, if not a significant tear, after catching a screen pass and cutting upfield. He is not expected back until after the Broncos' second preseason game Aug. 21 against Detroit.

Buckhalter seemed to suffer stinger-like symptoms in the same practice. He has been medically cleared to practice. But with the NFL mandating greater caution to injuries near the head and neck, the Broncos are expected to keep Buckhalter out until Monday.

The Orange is back.

Unlike his predecessor, Mike Shanahan, McDaniels likes the alternative orange jersey so much, he's going to have his players start in them.

The Broncos will break out their alternative orange home jerseys for their first home preseason game Aug. 21 against Tony Scheffler and the Lions at Invesco Field at Mile High. The home orange also will be worn twice during the regular season — Oct. 17 against the New York Jets and Dec. 5 against the Kansas City Chiefs.

Shanahan didn't care for the jerseys, mostly because the team lost in a key 2004 home game to the hated Raiders in a snowstorm.

The Denver Broncos, who shipped Arrington to the Birds for linebacker Joe Mays, lost top running backs Knowshon Moreno and Correll Buckhalter to injury at practice. Moreno could have a torn hamstring.

"It is ironic," Arrington said. "You just never know."

While Arrington was describing the micro-fracture procedure on his right knee and what it felt like to be in shoulder pads and contact work for the first time since Super Bowl XLIII, when he rolled for the Arizona Cardinals, the Eagles scooped up the back they cut to make room for him.

Realizing the Broncos needed a running back, the Eagles rescinded waivers on Martell Mallet, positioning them to make another deal.

"We changed our minds," general manager Howie Roseman said.

Just when it seemed the Eagles' slickness would pay off, running back Mike Bell injured his left hamstring running out a reception. Bell appeared to be taking the pain quite personally.

"He was playing really well," Eagles president Joe Banner said. "He feels like he's got a fresh start. There's

a sense of frustration. I'm sure he's frustrated but I'm sure it's not a long-term thing."

The Eagles aren't exactly married to Arrington, who they inquired about before he re-signed with the Broncos this year, or Mallet, the 2009 Canadian Football League rookie of the year who dropped too many passes at training camp. But with Bell shelved a quick move at running back would seem out of the question.

For a guy who hasn't played since the 2008 season, Arrington ran pretty well at practice. And he likes the idea of playing for the Eagles. After the shock wore off - Broncos head coach Josh McDaniel personally gave him the news of the trade - it was great to feel wanted by the team he admired as a kid in Rocky Mount, N.C.

"When I grew up the Eagles were my favorite team," Arrington said. "We didn't have the Panthers yet. They came around in 1996. Randall Cunningham was my favorite quarterback. I remember him and Bobby Taylor and all of those guys.

"(My agent) said the [Eagles] have pretty much been asking about me the whole offseason. This is one of the teams I was going to come to before I signed back this year with Denver."