Vikings defensive tackle Kevin Williams, barring a setback, will return from a knee injury Sunday against the Chicago Bears.

Williams practiced for the second consecutive day Thursday on a limited basis. Coach Leslie Frazier wants to see how Williams responds on Friday but is optimistic.

"So far, so good," Frazier said. "If everything goes fine [Friday], looking forward to him playing on Sunday."

Williams missed the opener in Detroit because of a right knee injury suffered on a low hit in the San Francisco preseason game. Frazier said Williams' knee had no swelling or pain after he practiced Wednesday.

The Vikings run defense struggled in Williams' absence in the opener as the Lions rushed for 117 yards.

"Kevin has been here forever," defensive end Jared Allen said. "Not having him on the field is different. Just having him back, I'm familiar with where he's going to be, especially if we're rushing. I know where he's going to be on certain blocks and I can play off that, and vice versa. We have that camaraderie. He's that centerpiece that kind of makes us churn. He has seniority and it's a respect thing."

Getting physical

Adrian Peterson didn't hesitate when asked what he thinks went wrong with the running game Sunday after his first carry went 78 yards for a touchdown.

"We kind of got beat up a little bit up front," said Peterson, who ran for only 15 yards on 17 additional carries. "Just not really executing, which when I looked at the tape was the biggest thing. Something we want to put behind us and not allow it to happen again."

Peterson was asked to compare Detroit's defensive front, which is one of the best in the league especially at tackle, to the Bears defensive line.

"They got some good D-tackles, but they're not Detroit up front," Peterson said. "Not to take anything away from those guys [in Chicago]. Julius Peppers and those guys are great players as well. We've got to go out and be physical and make our presence felt."

Rollout question

Offensive coordinator Bill Musgrave called for Christian Ponder to roll out to his left on a third-and-1 call in the third quarter Sunday. Under pressure, Ponder threw high and behind tight end John Carlson.

Despite criticism of play calls that require Ponder to roll out to his left, Musgrave said he believes his quarterback is comfortable in those situations.

"Well, I can think of a number of times in which he's made terrific throws going to his left," Musgrave said.

"First play that he ever started a game a couple years ago his rookie year would be one. But we're always working to be better."

Musgrave was referring to Ponder's 72-yard pass to Michael Jenkins against Green Bay on his first play as an NFL starter in 2011.

First-game nerves

Rookie Jeff Locke's first NFL punt traveled only 36 yards, and for the game Sunday he averaged 42.2 yards on five attempts.

"I think he was a bit nervous," special teams coordinator Mike Priefer said. "Even though we were indoors, I think it was just under the lights in the NFL for the first time. I'm not making excuses for him, and he wouldn't do that himself."

Things don't get any easier Sunday. Not only is the game outdoors, Locke is kicking to the best returner in NFL history in Devin Hester, who owns the league record for career punt return touchdowns with 12.

Teams often attempt to kick it out of bounds when facing Hester, but Priefer said that also poses problems, especially for young punters.

"If you tell them, 'I want it out of bounds, it's Devin Hester,' next thing you know it goes 22 yards, and you don't want that either," he said. "So there's a fine line between how much coaching you do in terms of how much direction you want to use. To me, if it's high and it's good hang time and decent distance, we should be OK."