The Vikings are still considering their options at middle linebacker, and will get a visit Tuesday from a familiar face.

The Green Bay Packers released inside linebacker Desmond Bishop on Monday, and he told ESPN Wisconsin he would visit the Vikings Tuesday.

Bishop, 28, missed last season because of a ruptured hamstring suffered in preseason.

The Vikings have given indications that Erin Henderson will move to middle linebacker this season after last year's starter, Jasper Brinkley, went to the Arizona Cardinals in free agency.

Bishop, who was taken in the sixth round out of Cal by the Packers in 2007, is now an unrestricted free agent.

He did not participate in the Packers' organized team activities or mini-camp this spring, but told ESPN Wisconsin that he was healthy.

The NFL.com story on Bishop is here.

The Vikings have a three-day mini-camp beginning Tuesday, so Bishop will get a good look at the team in action.

Mike Priefer had a lot to be proud of in 2012. For starters, the Vikings’ special teams coordinator refined Blair Walsh’s technique and helped turn the rookie kicker into an instant Pro Bowler.

On top of that, under Priefer’s direction, the Vikings had a pair of solid coverage units, ranking ninth in the NFL against punt returns (8.3 yards per return) and seventh in total kickoff return yards allowed (795). At one stretch, opponents went 10 consecutive games without returning a kickoff past the 25.

Now heading into 2013, Priefer has a supply of new weapons to experiment with. And as always, he is overflowing with enthusiasm as he pieces things together and prepares for this week's three-day mini-camp at Winter Park.

Recently, we had the opportunity to pick Priefer’s brain on several new additions to his unit.

Cordarrelle Patterson

What’s so special?: The Vikings feel Patterson can quickly become a barrel of dynamite on kickoff returns, which was a significant factor in their decision to trade back into the first round of the draft to nab him. And it’s no surprise that both General Manager Rick Spielman and coach Leslie Frazier have emphasized that Patterson’s biggest 2013 contributions will likely come as a return man.

So what stands out about the 6-foot-3, 205-pound receiver? Said Priefer: “Size. Strength. Speed. The ability to change direction. For a man that big to be able to change direction like he does is pretty special and unique.”

Priefer saw only two elite return men in this year’s draft: Patterson and Tavon Austin, who’s now with St. Louis. Now it’s the coordinator’s job to groom Patterson as the Vikings’ big weapon.

“Kickoff return-wise, he has all the abilities and tools right now to be a factor,” Priefer said. “A major factor.”

You should know: While Patterson is probably the front-runner to be the opening day kick returner, the Vikings are taking a wait-and-see approach on punts. At rookie mini-camp in May, Patterson showed enough deficiencies to give the coaches pause. Most notably, Priefer has identified fundamental flaws in how Patterson uses his hands and positions his elbows as he fields punts.

Those areas will take on even greater focus in training camp, when (presumably) the team will have greater opportunity to be outdoors than it had during OTAs.

“We just have to break the bad habits,” Priefer said. “Like anything else in football, you start by breaking the bad habits and then building up new good habits to supply a good foundation.”

Extra point: In nine games last season, Percy Harvin averaged 35.9 yards per kickoff return and opened a Week 4 win in Detroit with a 105-yard score. Priefer sees similarities in Harvin’s ability to change direction at top speed and Patterson’s. But he doesn’t want the comparisons getting too big.

“It’s going to be incredibly difficult to replace a guy like Percy to be quite honest with you,” Priefer said. “And so I think it would be unfair for me or anybody else in our organization to come out and say, ‘OK Cordarrelle, you’re going to replace Percy Harvin.’ That’s not fair to him. But I am excited about his ability and the direction we’re going.”

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Jeff Locke

What’s so special?: Locke’s leg strength is solid. But the rookie punter’s quest to learn is off the charts. And that’s an instant way to win the always-exuberant Priefer over. During the pre-draft process, Priefer and Locke first met at the Senior Bowl in January, then spent significant time together a month later at the combine and built even more camaraderie during a one-on-one on-campus visit and workout at UCLA in March.

“I always talk a lot about understanding your craft and having the ability to talk intelligently about it and make changes and make corrections,” Priefer said. “Jeff has all that. He has all the intangibles I was looking for.”

You should know: Priefer spent significant time picking the brain of UCLA special teams coordinator Jeff Ulbrich, who spent 10 years with the 49ers as a special teams contributor and was a special teams assistant with the Seahawks for two years. UCLA coach Jim Mora Jr., a former head coach with the Seahawks and Falcons was also a valuable sounding board in the evaluation of Locke. Then, Priefer zoned in on Locke’s approach, interested in part in seeing “how he rebounds from those punts that are less than perfect.”

He came away impressed with Locke’s attitude, leadership and hunger to get better.

“He has an NFL-ready mental approach to the game,” Priefer said. “He’s already a pro in that regard. We have to wait and see what he delivers as a punter.”

Extra point: Why, after eight solid seasons, was it time to let Chris Kluwe go? Priefer said he had met with Kluwe in both the 2011 and 2012 offseasons calling for greater consistency and productivity. At the end of last season, the special teams coach didn’t feel Kluwe had met the demands.

“We didn’t get the results we wanted. So we made a change,” Priefer said. “Nothing against Chris personally. That’s the NFL. You’re measured on productivity. If I don’t do my job there, I’m going to lose it. And in order for me to do my job better, I felt we needed an upgrade at that position.”

Priefer also felt an urge to plan ahead with the 2014 and 2015 seasons removing eight indoor contests from the Vikings’ schedule as they move home games to TCF Bank at the University of Minnesota.

“There has been a portrayal in the media that Chris and I were enemies,” Priefer said. “In my opinion, nothing could be further from the truth. I respect the guy. I think he’s done great things in this league. And I respect him for his views and opinions just as he think he respects me for mine. We just needed a change.”

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Joe Webb

What’s so special?: Webb’s freakish athleticism has always had the attention of Vikings’ coaches and teammates. Now that Webb is out of the quarterbacks' room and attempting a transition to receiver, Priefer is downright giddy to have access to the eager 6-foot-4, 220-pound playmaker.

“You look at his skill set and you say, ‘Ya know what? We can do some things with this guy,’” Priefer said. “So for me, I get fired up about having a guy like him playing special teams.”

You should know: So just how will Priefer utilize Webb?

“You take an athlete like Joe,” the coordinator said, “and my creative juices start flowing immediately.”

Webb might be an option as a kick returner. There are also thoughts of trying him on the edge on the field goal block unit and he could be deployed as a punt team gunner. To which Priefer notes: “We joke around about whether he’ll ever make a tackle when that opportunity comes.”

Priefer thinks Webb would, impressed with his size and strength. But he also knows there’s a place for receiver gunners who are skilled at getting upfield to force fair catches.

“Some of them don’t ever make a tackle,” Priefer said. “But they’re so good at what they do that if the punt is where you want it and it has good hang time and you don’t outkick the coverage, that gunner is standing there a few feet from that returner and now there’s no choice.”

Extra point: Finding a niche on special teams may be a pre-requisite for Webb to stick on the 53-man roster. After all, the Vikings are only likely to keep five, possibly six receivers around. And with Patterson, Greg Jennings, Jerome Simpson and Jarius Wright in the mix, Webb may have to fend off the second tier of receivers, a group that includes Stephen Burton, Greg Childs, Chris Summers and Rodney Smith. 

In a push to heighten safety, the NFL and the Vikings have announced new provisions on what can and cannot be brought into stadiums on game day. The Vikings are also looking to find new ways to speed up and smooth over the process of fan entry into Mall of America Field.

This afternoon, the organization issued a release on both issues. Here's an excerpt from that bulletin:

• Bags that are clear plastic, vinyl or PVC and do not exceed 12” x 6” x 12.” (Official NFL team logo clear plastic tote bags are available through club merchandise outlets or at nflshop.com) 
• One-gallon clear plastic freezer bag (Ziploc bag or similar).
• Small clutch bags, approximately the size of a hand, with or without a handle or strap, may be carried into the stadium along with one of the clear bag options.
• An exception will be made for medically necessary items after proper inspection at a gate designated for this purpose.

 The Vikings will hold their 10^th and final Organized Team Activity on Thursday at Winter Park before reconvening next week for a three-day mini-camp. And as the offseason program enters the finishing stretch, third-year quarterback Christian Ponder continues zeroing in on making good reads more consistently.

On Wednesday afternoon, before teeing off at the team’s annual golf outing, an event that benefits the Vikings’ Children’s Fund, Ponder was asked how he’s measuring himself during this OTA stretch.“

The biggest thing is decision making,” he said. “Obviously you want to complete as many balls as possible, especially in things like 7-on-7. But we’re being put into some hard situations as well. Third-and-long. Blitz. A lot of blitz drills and everything. So it’s tough. I think the defense definitely has the upper hand in these drills. But it’s good for us to see that. And it makes the quarterback make smart decisions and get the ball out quick. So you want to see completions and the right decisions.”

Ponder knows the bar has been raised for him in his third year as a starter. And with back-up Matt Cassel now in the picture, his leash might not be quite as long in 2013 if his struggles are extreme. Still, the Vikings quarterback said the key in May and June is to feel things out within the offense without feeling exorbitant pressure.

“This is a time for us as an offense to just try a bunch of new stuff and see what sticks and see what we like,” Ponder said. “And there are a lot of new plays going in and everything. So it’s a fun time. It’s fun to try out quirky plays and see what the defense does. And the defense is doing the same thing, running funky coverages and everything. But our mindset is we want to get better every day and see a progression heading into training camp.”

Injury update

On the injury front, Vikings coach Leslie Frazier reported that Chad Greenway’s Thursday morning arthroscopic surgery to clean up his left knee went well as expected. Greenway will be out of action until training camp begins in late July.

Fellow linebacker Nate Williams, signed in April as an undrafted free agent, has also undergone minor ankle surgery and, according to Frazier, will be sidelined until camp opens in Mankato as well.

The Vikings have their share of injuries to keep tabs on, especially with Pro Bowl defensive end Jared Allen continuing rehabilitation on his left shoulder in which he had a labrum tear repaired shortly after last season ended. Allen has been at Winter Park the past two weeks but not on the practice field. And he won’t be back in action during mini-camp next week either.

But Frazier said Wednesday he anticipated very few injury issues to still be a concern when the team reports to Mankato. The longest shot to be ready may be second-year receiver Greg Childs, who continues attacking his recovery from torn patellar tendons in both knees.

Frazier said after Tuesday’s practice that he isn’t certain how quickly Childs will receive medical clearance to return to full action but won’t rule out the receiver getting back to practice early in training camp.

"I have my fingers crossed, hoping that that will happen," Frazier said. "I'm waiting on [head athletic trainer] Eric Sugarman and our medical staff to give us the green light. But that would be my hope. We'll see what happens. I'm not sure what direction it will go."

Center of attention

On Wednesday, Frazier also noted that the team is closely monitoring the progress of standout center John Sullivan, who had microfracture surgery on his left knee.

In Sullivan’s absence during OTAs, the Vikings have tinkered with back-up plans at center. Veteran Joe Berger has seen work there. In addition, Brandon Fusco, who started all 16 games at right guard and is the expected starter there for 2013, has also handled snaps.

“We don’t see any problems with Sully being ready to go,” Frazier said. “But you want to make sure that you have other guys prepared.”

Fusco was a center during his college career at Slippery Rock and could be an option at the position if Sullivan’s recovery was to hit an unforeseen snag or if he had any lingering knee issues that sidelined him during the season.

Sliding Fusco to center, of course, would then open up the competition at right guard where rookies Jeff Baca and Travis Bond as well as veteran Seth Olsen could figure into the mix.

Still, Frazier believes Sullivan’s recuperation will stay on track which would give the Vikings the luxury of opening training camp with the same starting offensive line that started all 16 games last year.

“We’ve still got to see a little more progress out of John Sullivan,” Frazier said. “He’s making progress. But we want to continue to see that. … You just want to see him continue to gain confidence and not be worried about the surgery but just move on. And he’s making progress. From everything that Eric Sugarman tells me, he’s on target. He’s moving in the right direction. And we’ve got enough time for him to continue to improve. Hopefully when we get started, he’ll be able to go full go right away.”