If the Vikings defensive alignment looked a little odd at points last weekend, Jared Allen's neck spasms probably had something to do with it. Unable to turn his neck in one direction, Allen spent part of Sunday's upset of San Francisco lining up at left end as opposed to his usual home on the right side of the defensive line. But that's not an experiment the Vikings plan to continue.

Said defensive coordinator Alan Williams: "I think guys should do what they do best. He's been on the right side and that's where he rushes from. Let the left tackle handle our best guy from the left side. I think you do what you do and don't try to outsmart yourself or out-trick yourself. And let the other team handle what you do best."

Williams said the suggestion to move Allen across the line came from the players with defensive line coach Brendan Daly signing off on the idea.

"It just worked out that we have some older vets that can problem solve on the sideline," Williams said. "That's a good thing, when they can come to you with a problem and an answer."

For what it's worth, Allen picked up his first sack of the season from his usual spot at right end late in the game against the 49ers, also forcing a fumble that Brian Robison recovered.

Allen was limited in practice Wednesday afternoon and is back on the practice field today.

Managing Megatron

Here's what Williams had to say about Detroit's superstar receiver Calvin Johnson and the need to devote extra secondary attention to him: "He's a big, tall, fast physical receiver who can stretch the field. So when that happens, it's tough to keep an extra guy in the box for the run. So you have to be able to shut down the run with seven or six defenders. And then you have to be able to stop him and take your shots, calculated shots, for when you want to rotate a guy into the box. It's a guessing game as to when they're going to take their shots and when they're going to run the ball."

Simply put

Williams noted that last week's impressive defensive effort against San Francisco was a byproduct of the Vikings' sharp focus in practice leading up to the game. The defense also did an outstanding job of keeping things simple, understanding the assignments and executing. Which is just how the first-year defensive coordinator wants it.

"I've always been someone to say that it's not the trick-'em type of things that win ball games. It's the fundamentals," Williams said. "It's blocking, it's tackling, it's doing your assignment, It's looking in the right place, executing. And when you do that, you always give yourself a chance. Athletically, most teams are fairly similar. It just comes down to who can do the fundamentals the best. And last week it was the Vikings."

The Vikings limited San Francisco to 280 total yards and forced a normally reliable 49ers offense into three fourth quarter turnovers. Williams was impressed with the way his defense ran to the ball throughout the game.

You know that old saying "Defense wins championships"? The Vikings believe in a deeper truism.

Noted Williams: "We always say that front side wins games, back side wins championships. So we want the back side guys to hustle and get there. And if our back side guys are running to the ball, we'll get those [takeaways] that are errant throws or tipped balls or balls that are on the ground. That's what we've been preaching since OTAs."

Injury update

Weakside linebacker Erin Henderson is sitting out of practice again Thursday, still not cleared to return after suffering a concussion in Week 2 at Indianapolis. The only other player not practicing today is safety Andrew Sendejo (ankle). Mistral Raymond, of course, will be out for the foreseeable future with a dislocated ankle. He is expected to miss 3-5 weeks.