NFL: 'Skins testing trio of aging runners

Last week, it was Clinton Portis. Now, Larry Johnson has a turn at the feature role in the crowded competition for playing time in the Washington Redskins backfield.

Johnson will start Saturday night's preseason game against Baltimore as coach Mike Shanahan continues to sort out how best to handle a trio of older running backs out to prove they're not past their prime.

"Larry's been very consistent," Shanahan said, "but I do see a sense of urgency this week. He's going to get an opportunity to showcase his talents."

The third back in the veteran mix, Willie Parker, will get to run with the first unit in next week's game against the New York Jets.

Johnson will turn 31 in November, Parker will be 30 in November, and Portis will turn 29 on Sept. 1.

Harvin back with Vikes. Wide receiver Percy Harvin returned to the Minnesota Vikings after an overnight hospital stay because of a scary migraine attack, though the date of his return to the field remains unclear.

Harvin was on the practice field Friday morning wearing a T-shirt, shorts, and tennis shoes, drinking Gatorade while smiling and chatting with coaches. He had been taken away by ambulance Thursday after getting sick and collapsing on the field, a sobering scene that prompted the Vikings to end practice early.

Harvin has missed all but a handful of practices since training camp began three weeks ago, plagued again by the unpredictable, debilitating migraine episodes that can leave him unable to function. But Harvin was, by all accounts, doing fine one day later.

"He probably could've come over here and done some things today, except for the fact that they've got a couple tests that they want to finish with," coach Brad Childress said.

Harvin will not travel with the team to San Francisco for Sunday's exhibition game.

Trade winds. Seattle has talked with San Diego about acquiring holdout wide receiver Vincent Jackson, a Seahawks spokesman said. The spokesman said that the Seahawks were granted permission by the Chargers to talk to the wide receiver a couple of weeks ago.

Jackson has not reported to training camp because he is unhappy with being a restricted free agent in San Diego. He wants a multiyear contract.

A Pro Bowler coming off his second straight 1,000-yard season, Jackson recently pleaded guilty to his second DUI since joining the NFL. He is suspended for the first three regular-season games.

Linebacker shuttle. The Jacksonville Jaguars placed linebacker Freddy Keiaho (concussion) on injured reserve and signed linebacker Alvin Bowen.

Bowen has been with Buffalo, Washington, and Seattle. He played in Seattle's preseason opener and was waived Aug. 17. He was a fifth-round draft pick by the Bills in 2008, then suffered a season-ending knee injury in the preseason.

Bill suspended. Buffalo tight end Shawn Nelson has been suspended four games for violating the NFL's substance-abuse policy. Nelson had 17 catches for 156 yards and a touchdown in 12 games as a rookie out of Southern Mississippi last season.