Defensive front must and should play better

Tarvaris Jackson floundered Monday. That's disappointing, but not shocking.

The Vikings gave up a punt return for a touchdown that might have cost them the game. That won't be their last special teams mistake of the season.

Adrian Peterson, despite rushing for 100 yards, had a restrictor plate placed on him in the second half by a focused Packers defense. That could be the norm when Jackson struggles.

Some aspects of the Vikings' 24-19 loss to Green Bay were either understandable or the stuff of NFL biorhythms, variables that make this the unpredictable league it is.

Most troubling for the Purple was that the heart of the team too often suffered from arrhythmia. What could become the NFL's dominant defensive line got beat on a few game-changing plays by the Packers' makeshift offensive front, rendering the Vikings' one supposedly sure advantage moot.

If the Vikings are to become a playoff team and justify the money owner Zygi Wilf spent this offseason, they will need competence from Jackson, and dominance from the defensive line. It was more surprising Monday that they lacked the latter.

"It's easy to say, but for a couple of plays where we had a guy who jumped out of a gap ..." Vikings coach Brad Childress said. "I was looking at their explosive plays. Without them, they had 122 yards. With them, they had 317 yards. ... That's that consistency part. We had a couple of missed tackles."

A quarterback making his first NFL start -- Aaron Rodgers -- completed 18 of 22 passes, didn't commit a turnover, didn't take a sack, and ran at will. A running back who was the only player to rush for 100 yards against the Vikings last year -- Ryan Grant -- carried 12 times for 92 yards.

Vikings defensive end Jared Allen forced two early holding penalties, which are almost as important as sacks, but he didn't make a noticeable play the final three quarters, and called it the least productive game of his career.

The Williams Bros., Pat and Kevin, each had six tackles and one tackle for loss, but did not measure up in the categories they care about most -- shutting down rushing attacks and winning games.

Defensive end Ray Edwards had four tackles and one quarterback hit, but didn't take full advantage of the presumed preoccupation of the offensive line with his linemates.

This summer, Allen promised to bury his helmet in Rodgers' back. Pat Williams promised to stuff Grant. Edwards promised to break Michael Strahan's record for sacks in a season.

The four linemen should keep speaking their minds. They just need to do a better job of fulfilling their predictions.

They'll get another prime chance to show off Sunday. They'll be playing at home, on turf, in front of a loud crowd, against another battered group of blockers. The Chicago Bears made the Colts line look tissue-thin on Sunday night. Peyton Manning, after not playing all preseason, looked gimpy and unsure. The Colts receivers, with Marvin Harrison looking older and slower, aren't as dynamic as they once were. Tight end Dallas Clark is out because of an injury.

One underrated aspect of the NFL is the importance of continuity. In a league where the fear of injury causes coaches to play their starters together for precious few preseason snaps, the first game of the season can be a mystery.

Eventually, though, Allen, the Williamses and Edwards will have to dominate games for the Vikings to become a playoff team. It wouldn't be surprising to see them start on Sunday.