MANKATO – Desmond Bishop hasn't overtaken Marvin Mitchell in the Vikings' competition at weak-side linebacker, but the former Packer is moving as well as he said he would when he reported to camp a week ago.

So far, there are no visible signs of any lingering effects of the torn hamstring that happened last summer and wiped out Bishop's entire 2012 season in Green Bay. He was active in Wednesday's padded practice, showing some burst on blitzes and knocking running back Toby Gerhart off his feet with a solid blast.

Bishop continues to be a backup, but for now the Vikings are just happy to see the hamstring hold up under contact and keep bouncing back the following day.

The Vikings also are happy with their health overall. The only players not practicing or dealing with an injury are the two players on the physically unable to perform list: receiver Greg Childs and linebacker Nate Williams.

"So far, so good," coach Leslie Frazier said. "We've kind of stayed away from the injury bug so far."

Seeking a fourth defensive end

The Vikings ended last season with five defensive ends and four defensive tackles on their roster. If they go with nine defensive linemen again this year, they probably will keep five defensive tackles, with rookie first-round draft pick Sharrif Floyd being the new addition.

With the top three defensive ends — Jared Allen, Brian Robison and Everson Griffen — already set, there probably is room for only one more. The competition for the fourth and final end spot could come down to George Johnson and Lawrence Jackson.

Johnson is working as the second-team right end, while Jackson is working as the third-team left end. But don't count Jackson, a six-year veteran, out. A quiet free-agent signing in April, Jackson arrived with 69 games of experience, including 25 starts and 19 ½ sacks. Johnson has played 11 games with no starts and no sacks.

Jackson was a starter in Seattle, where he was a first-round draft pick, and a reliable role player in Detroit the past three years. He had a career-high six sacks in 2010.

"[Jackson] is a guy we think has pass-rush ability from the tapes that we saw from when he was up in Detroit," Frazier said. "We want to see how he handles the run. … How consistent he can be both as a run defender and a pass rusher. In our league, the more pass rushers you can get, the more you want. You never want to turn down pass rushers."

Sanford calls Harvin

Vikings safety Jamarca Sanford said he called friend, former teammate and current Seahawks receiver Percy Harvin as soon as he heard Harvin needed hip surgery that could wipe out his entire season.

"It'll take him a couple of days for it to sink in," Sanford said. "But overall he's in good spirits now. He's looking forward to getting the surgery over with and coming back strong. He'll be back."

The normal recovery time for a surgery of this nature is 12 to 16 weeks. The Vikings play at Seattle in 15 weeks (Nov. 17), but it's unlikely Harvin would be ready to play by then.

"I was looking forward to playing him," Sanford said. "We had some battles back in college."

New bag rule in effect

Starting with their Aug. 9 preseason home opener, the Vikings will be adhering to the NFL's new policy that limits the size and types of bags that fans will be allowed to bring into the stadium on game days. Here's what will be allowed:

• Clear bags that do not exceed 12 inches by 6 inches by 12 inches. The Vikings will send season-ticket holders a bag of this size with a team logo on it.

• One-gallon clear plastic freezer bag. Zip-lock bags will be available at the stadium.

• Small clutch bags, about the size of a hand, with or without a handle or strap, can be brought in along with one of the above clear-bag options.

Exceptions will be made for medically-necessary items. For more information, go to NFL.com/allclear.

Etc.

• Fullback Jerome Felton returned to practice Wednesday after missing all of Tuesday and part of Monday's practice to handle a personal matter.