– A 13th consecutive practice in full pads opened Monday with Vikings players playfully chanting “Shells, shells, shells” in an effort to get coach Leslie Frazier to let them take their shoulder pads off and wear only the soft material that goes underneath.

Defensive players, led by Jared Allen, Kevin Williams, Brian Robison, Chad Greenway and Jamarca Sanford, appeared to be the instigators. The chants began during stretching and continued into the early portion of individual drills.

Frazier smiled a lot but didn’t relent. The pads stayed on.

“I was positive it wasn’t going to work,” Robison said. “We’re wanting shells, but Frazier … I guess we’re going to have it like Burger King and have it his way.”

Frazier has been hearing calls for shells for about a week now.

“We’ll see if we relent before we break camp,” Frazier said. “I have a feeling we won’t, but we’ll listen though.”

Frazier has kept the players in pads partly because this has been the coolest weather for training camp in memory with temperatures in the 70s, low 80s and even a few in the 60s. The NFL’s new collective bargaining agreement (CBA) also calls for one day off a week and for only one practice a day and one walk-through.

“This new CBA and then you get weather like this?” Frazier said. “Man, this is a player’s dream.”

But it’s not a coach’s dream.

“I like a little heat,” Frazier said. “I think it’s good for our linemen to sweat a little bit. But, hey, we deal with it. … We’ve gotten quality work, but I can’t remember having this many consecutive days like this.”

Asked if he tells any “back-in-my-day” stories to today’s players, Frazier — a cornerback for the Bears in the 1980s — said, “Oh yeah, we talk a little bit about that. And a few guys, like Kevin Williams, he remembers what it was like with two-a-days and hitting every day. But there’s not many more. Even the guys coming from college, they don’t know what it’s like to go back to back to back. It’s a dying breed.”

Mixed punting

Rookie punter Jeff Locke averaged 39.2 yards on five punts with a long of 48 in Friday night’s preseason opener. Special teams coordinator Mike Priefer was both pleased and not so pleased.

“We had two [punts on the other side of the 50], the one fair caught at the 10 and one at the 7, which were outstanding punts,” Priefer said. “The 48-yarder had a 4.6-second hang time, which is a good punt. His last two punts [38 and 39 yards] were not very good.”

Evaluating Mitchell

On a team that plays as much if not more nickel than base defense, it can be hard evaluating the linebacker who comes off the field in the nickel. That linebacker at this point is Marvin Mitchell, a seven-year veteran who has started only four NFL games.

Mitchell got only six snaps in Friday night’s 27-13 loss to Houston.

“Marvin has taken steps forward from last year,” defensive coordinator Alan Williams said. “I think he feels more comfortable being around as part of the guys. We’re seeing the leadership qualities in Marvin come out, not only on defense but special teams. Marvin is playing good ball for us. Hopefully, we’ll get more base defense with that first defense and not as much nickel as we did last week with that first group.”


• If NFL MVP honors weren’t enough, Adrian Peterson now has his face on a Wheaties box. Limited edition boxes will be available in stores this week. “I am blessed and fortunate to have such an incredible honor,” the Vikings running back said in a release.

• A year ago, the Vikings had the fifth-fewest penalties (90) in the league. They kept the trend going Friday night with only one penalty. They had a penalty shutout going until third-string tackle Demarcus Love was called for holding late in the game. Said Frazier: “The fact that we had one penalty in an opening preseason game, that was very, very encouraging.”

• Former Vikings kicker Ryan Longwell is going to retire with Green Bay, the Packers announced. Long­well kicked for the Packers from 1997 to 2005 and scored a team-record 1,054 points before playing for the Vikings from 2006 to 2011. The Vikings released Longwell last year after drafting eventual All-Pro Blair Walsh.