In the new look, Williams slides into a coverage position and Johnson teams with veteran Darren Sharper as the safeties.

Williams played cornerback early in his career and is considered a good matchup against tight ends. Having six defensive backs on the field leaves Ben Leber as the sole linebacker.

PLAYER NOTES

--DE Jared Allen said Wednesday he has a grade-3 sprain of the AC joint in his right shoulder, meaning it's the most serious sprain and could indicate a torn ligament. Allen did not practice Wednesday and there appears a good chance he won't' be able to play Sunday against Green Bay. A grade-3 sprain means there is often a two-to-four week period for recovery.

--DT Brian Robison is being used all along the line by the coaching staff. Robison is normally a right end but he's also begun playing tackle at times in passing situations. Robison is speedy at 6-3, 259-pounds and presents problems for interior offensive linemen. He likely will start at right end Sunday if Allen can't go.

--S Husain Abdullah was limited in practice Wednesday because of a neck injury.

--LB David Herron was limited in practice Wednesday because of a hip injury. Herron has not played in the past two games.

--TE Garrett Mills was limited in practice Wednesday because of an ankle injury that sidelined him for the Vikings' victory over Houston last Sunday.

--WR Robert Ferguson had an excused absence Wednesday because he was tending to a personal issue.

GAME PLAN: The Vikings offense has started to achieve the type of balance that Brad Childress envisioned when he took over as coach in 2006.

Wide receiver Bernard Berrian, signed as a free agent this offseason, has provided the type of down-field threat the Vikings were hoping to get and has averaged 20.7 yards per catch.

This doesn't mean opposing defenses have stopped putting eight men in the box against running back Adrian Peterson, but at least quarterback Gus Frerotte has been able to make teams pay when they do decide to focus solely on the run.

The Vikings' main priority is to establish the run, and that certainly isn't going to stop against the Packers. Minnesota is averaging 134.5 yards per game, sixth in the NFL, and the Packers are 27th in the league against the run. Green Bay is giving up 146.4 yards per game on the ground.

Defensively, the Vikings are coming off a game in which they gave up 363 passing yards to Houston but were pleased because for the most part they contained Texans Pro Bowl receiver Andre Johnson (four receptions, 62 yards, one touchdown).

The Vikings claimed their plan was to give up passes underneath in exchange for stopping the big play. This meant Texans tight end Owen Daniels caught 11 passes for 133 yards.

The Packers, no doubt, will attempt to take advantage of this and have Aaron Rodgers get the ball to his receivers and hope for yards after the catch.

Green Bay's Ryan Grant rushed for 119 yards in a 34-0 victory over the Vikings last season and had 92 yards in the season opener. However, the Vikings run defense is among the best in the league and getting yards on the ground usually isn't all that easy.

MATCHUPS TO WATCH: Vikings RB Adrian Peterson vs. Packers run defense - Peterson has rushed for 100 yards in five of eight games this season and will be looking to add to that total against a team that is giving up 146.6 yards per game. The Packers will be hoping that middle linebacker Nick Barnett, among others, will be able to contain Peterson by pinching up toward the line and controlling the run. Peterson went for 103 yards in the Vikings' regular-season opener against the Packers at Lambeau Field.

Vikings RT Ryan Cook vs. Packers DLE Aaron Kampman: Cook has had an up-and-down season and will get another test going against Kampman, a standout for the Packers. Kampman had one sack in the Packers' season-opening victory over the Vikings and has six on the season. He had 12 in 2007. The Vikings are likely to get Cook some help from either tight end Jim Kleinsasser or a running back.

Packers TE Donald Lee vs. Vikings LBs Chad Greenway and Ben Leber: Houston Texans tight end Owen Daniels had 11 receptions for 133 yards last Sunday against the Vikings, which is something the Packers surely noticed. Lee is the Packers' top tight end and has 22 catches for 163 yards and two touchdowns. Greenway and Leber will be largely responsible for covering Lee, and they need to do a better job this week.

INJURY IMPACT: Pro Bowl defensive end Jared Allen said Wednesday he has a grade-3 sprain of the AC joint in his right shoulder, meaning there is a good chance he won't be able to play Sunday. This would be a huge loss for the Vikings and means Brian Robison likely would start at right end. Allen is tied with defensive tackle Kevin Williams for the team lead with seven sacks. More than a week after Fox Sports reported Pro Bowl defensive tackles Kevin and Pat Williams were facing four-game suspensions for taking a banned diuretic, there has been no word from the Vikings or the NFL about their situation.