Terrell Davis, the NFL’s premier running back of the late ’90s, is so discouraged with the lack of progress on his injured knees that he’s contemplating retirement.

“I’m taking everything in stride, and whatever way the wind blows I’m fine with it,” said Davis, who has been plagued by injuries since 1998, when he became just the fourth player ever to rush for 2,000 yards in a season.

Dallas' Emmitt Smith, right, kids around with former teammate Deion Sanders during the Cowboys practice. Sanders visited the team Tuesday at the Alamodome in San Antonio.

“I’ve reflected on a lot of things I’ve done and things I’m going to do. and it’s not everything in life. I mean, it was fun while it lasted and if it was meant to be the end, then hey, it was meant to be the end.”

Davis seemed ready to start this season as Denver’s No. 1 back. But his right knee began to swell during camp and recent tests found no basic reason for it.

“At some point in time, Terrell has to look at himself and ask, ‘Does it continue?”‘ tight end Shannon Sharpe said. “At some point, you have to realize that, ‘I’ve had a great career. Maybe it’s time to focus my energy on something else.’ That’s a hard decision because it’s something you’ve basically been doing all of your life, and suddenly you aren’t doing it anymore.”

Lions

Offensive tackle Stockar McDougle will be out 2 to 3 weeks with an injured left knee.

McDougle, a former first-round draft pick who has been hampered by injuries during his two NFL seasons, was injured during a practice on Monday, but was able to walk off the field.

“It’s a little worse than we expected,” Lions coach Marty Mornhinweg said.

Packers

Right tackle Mark Tauscher injured his right elbow, worrying coach Mike Sherman for a while, but X-rays were negative and Tauscher only had a forearm bruise.

Sherman initially feared a fracture or a torn ligament.

“He hit a nerve going up to his arm and it scared him a little bit, scared us a little bit, but he’s going to be fine,” Sherman said.

He said he didn’t know how long Tauscher would be sidelined, “but knowing Tauscher, it won’t be very long.”

Colts

Wide receiver Marvin Harrison and kicker Mike Vanderjagt did not practice Tuesday morning with the Indianapolis Colts. Harrison returned for the afternoon practice.

Both players were excused by coach Tony Dungy so they could attend to personal matters in their hometowns of Philadelphia and Toronto.

Dungy did not elaborate on Harrison, who has had three straight 100-reception seasons and is trying to become the first player in NFL history to have four straight seasons with at least 100 receptions.

When the Colts returned for a short afternoon practice, Harrison was back.

Cowboys

Derrick Harris had his first practice with the Cowboys, a day after signing with them to bolster Dallas’ depleted fullback corps.

Rookie Jamar Martin suffered a season-ending knee injury on the second day of camp, and converted linebacker Scott Zimmerman was lost for four weeks with a high ankle sprain sustained in Friday’s preseason win over Oakland.

That left the team with only one player at the position Robert Thomas, who himself is coming off an ankle injury that limited him to only five games in 2001.

“I’ve got confidence in Robert Thomas,” coach Dave Campo said Tuesday. “We had the opportunity to bring in a veteran guy because we want competition there.

“(Harris) does some things that we like,” the coach continued. “It’s good for Robert (Thomas) to see that.”

Titans

Wide receiver Derrick Mason gave the Titans a brief scare when a teammate kicked his right leg during practice, and the receiver temporarily lost feeling from the knee down.

Mason, who had 1,128 yards receiving last year as the team’s first receiver over that plateau since 1991, grabbed at his knee, and said he was worried when he couldn’t feel anything in his lower leg. But a team trainer checked him out and told him the nerve near the knee had been stunned.

The feeling started coming back within a minute, and Mason said he felt fine three minutes later.

“Obviously, there were a lot of deep breaths for a little bit, but Derrick is fine,” coach Jeff Fisher said. “He’ll be fine. He could’ve practiced.”