The Marshawn Lynch highlight reel isn't one the Vikings defense was eager to load up this week. Not with its sudden struggles stopping the run.

If Tampa Bay rookie Doug Martin sprung loose for 214 yards from scrimmage last week, won't the challenge Sunday be even greater trying to corral Lynch, a 215-pound bruiser who runs like a Pamplona bull?

If Arizona's LaRod Stephens-Howling was able to register his first career 100-yard game against the Vikings two weeks ago, what might happen with a Pro Bowl-caliber back such as Lynch, who has 16 100-yard outings on his résumé?

Said linebacker Chad Greenway: "When you're struggling against the run game like we have the last few weeks, all you want to do is test yourself. That's the only way you can get out of your funk."

Over the past three weeks, the Vikings have allowed opponents to rush for 468 yards. They have struggled with tackling and they have been lax with their assignments.

Now they'll head into hostile territory in Seattle this weekend to butt heads with a back nicknamed "Beast Mode."

Were it not for Adrian Peterson's impressive resurgence, Lynch's 757 rushing yards would lead the NFL right now. And his highlight queue is full of rattling runs that would put even the most tenacious defense on edge.

Of course, there's Lynch's most renowned rumble, from a 2011 NFC playoff game against New Orleans. That one covered 67 yards as he pinballed all across CenturyLink Field with a half-dozen Saints getting their hands on him but never able to bring him down.

But there's also Lynch's most recent touchdown, too. That went 77 yards in Detroit last Sunday with the Seahawks back finding a crease on the right side, darting through and sprinting untouched to the end zone.

Still, Vikings defensive coordinator Alan Williams said Thursday it's not the long touchdown runs that define Lynch. It's that he's constantly pounding away, like a wrecking ball razing an office park one thump at a time.

"Usually his best plays," Williams said, "are the ones that are 10 or 15 yards, where there's nothing there and he may sidestep a guy, jump cut, shimmy through a hole, maybe run over a guy and pick up an extra 4 or 5 yards. He does a great job after contact."

Right place, right time

The Vikings are certain they know what's malfunctioned in their defense the past two weeks: gap control.

That's why coach Leslie Frazier used a chunk of Monday's practice to review the defense's run fits. It's also why Williams and his players have continued singing the same refrain throughout the week.

"Do your job," safety Jamarca Sanford said. "Everybody has to do their own job without worrying about trying to do other guys' jobs. We do that, we'll be just fine."

Sounds logical. Seems like a simple fix.

"It's so easy, it's hard," Williams noted.

After all, it doesn't take much for one small crack in a defense to become a giant crevice. Especially when a handful of eye-opening big runs start to elevate the urgency.

Said Williams: "Guys start saying, 'Well, you're in an eight-man front, you should be able to stop the run. It got out. What happened? Maybe I should do something else to stop it.' "

Keeping it together

Defensive end Jared Allen said Thursday he doesn't think it becomes contagious when one defender drifts out of his gap. But that might be semantics. Because Allen did acknowledge "a domino effect" for such mistakes.

"If one guy gets out of his gap, that guy's [blocker] might be up on a linebacker. And now the linebacker has to try to figure out how he's going to get through that guy to get to his gap. It's just a domino effect. Now you've got two guys out of their gaps and that's when things go awry."

Naturally, the message this week to every player on every unit of the defense has been to stay in place, to not vacate the assigned gap until the play has passed it.

"When you try to do too much," Williams said, "usually you don't take care of first things first."

Williams now has video evidence of the Vikings struggles to back that point. He also has film of Lynch to further drive the message home.