Vikings defense still sticking to basics

Before Vikings defensive coordinator Alan Williams talked to reporters Thursday, he chatted with defensive end Brian Robison and safety Jamarca Sanford. Williams said he didn't single them out before he spoke to the media, but his message to them was one for the entire defense: Stick to the plan.

"We're still building the foundation to win football games, and we want this to be the model of the NFL," Williams said. "To be that, you have to build a firm foundation. You have to go through, sometimes, some growing pains, which we are right now. You don't want it, but to build something solid, sometimes you have to go with that."

Williams stressed the defense has to continue practicing hard and focusing on details despite the lack of results. The Vikings are 30th in the NFL in total defense this season, allowing 401.6 yards a game. Last year they were 17th (350).

The Vikings give up 287.9 passing yards a game, 29th in the league, but Williams said the secondary shouldn't work outside of the defensive structure.

"Sometimes when you're maybe not getting interceptions or playing as well as you think you should, you're thinking, 'I need to do more. I need to go over here and make up for someone else,' " Williams said. "My message is, don't do that. Be more detailed and if we tackle better, if we run to the ball more, if we execute assignments better, the results will be better. That's one thing that we continue to reinforce."

The unit has seven interceptions this season but none in the past three games.

Adrian Peterson will return to Texas this weekend when the Vikings face the Cowboys at AT&T Stadium.

"It is what it is; I don't really get into it that much," Peterson said. "Some of them, I'm sure they're going to root for me as well, but if the Cowboys win, that's what they're going to be hoping for."

He doesn't have plans to make a stop in his hometown of Palestine, Texas, about two hours southeast of Dallas, and will treat this game like a business trip.

Peterson said he feels comfortable with his injured hamstring despite some tightness. He used a heat pad on the sideline for the first time to help loosen the hamstring last Sunday against the Packers, and he will have the same routine against the Cowboys.

"Once I get warmed up and get going, that's going to be the most important thing," Peterson said. "Last week, stretching it a lot, putting some heat on there and getting past that warmup stage and loosen the muscle up, and I was able to do that last week and it felt good."

• Cornerback Chris Cook and Sanford did not participate in practice for the second consecutive day. Coach Leslie Frazier said he hoped they'd be cleared for Friday's practice and wouldn't decide on any roster options until then.