Five things to watch vs. Cowboys

The Cowboys are a good opponent for the Vikings in the third preseason game. As the dress rehearsal for the regular season, it's the only preseason game in which there's game-planning and starters playing into the third quarter.

The Cowboys come to Mall of America Field on Saturday night with a pass-oriented offense and a 3-4 base defense. That's what the Vikings will be looking at when the regular season opens in San Diego on Sept. 11. Granted, the Cowboys' starting corners -- Terence Newman (groin) and Mike Jenkins (shoulder) -- and No. 1 receiver -- Miles Austin (hamstring) -- won't play. But the offensive and defensive concepts are similar to what the Vikings will face in San Diego. The most obvious difference, of course, is the Vikings will be attacking Tony Romo and the Cowboys' offense with the benefit of the home-crowd noise behind them.

Here are five areas to watch tomorrow:

1, The offensive tackles versus OLB DeMarcus Ware.

Ware might be the best outside linebacker in the league. At least the best among people not named James Harrison. New defensive coordinator Rob Ryan has ramped up the Cowboys' attack mode and will try just about anything to give teams looks they aren't expecting. He's not going to show all he's got up his sleeve in a preseason game, but he will move Ware around. That means left tackle Charlie Johnson and right tackle Phil Loadholt both will be tested by one of the best pass rushers in the league. It will be a good measuring stick to see where this line is two weeks from the regular season.

2, Handling a top quarterback.

One could argue that Romo is a tad (or more) overrated. He's got a 95.5 career passer rating, but he's also won just one playoff game in five years as a starter. And he was timid and just plain awful in that playoff loss at the Metrodome in January of 2010. But Romo and the Cowboys like to throw the ball out of multiple formations. They also like to use their tight ends -- as San Diego does -- so it will be interesting to see the linebackers and safeties covering the likes of Jason Witten and Martellus Bennett. Rookie right tackle Tyron Smith, the ninth overall pick, is starting at right tackle. He's looked good so far, so watch how new left end Brian Robison does against him.

We're two weeks from the regular season opener and there are still heated position battles that are dead heats. No. 2 quarterback, strong safety, the third and fourth corners, the Nos. 4-5 receivers, punt returner and right guard are still up for grabs. "We have some key decisions to make at certain positions," coach Leslie Frazier said. "And this game -- as I told our team -- will play a major role in determining where people are going to fit on our squad. It's a big ballgame for a lot of our players and also for our coaches. We're trying to shape our roster, so we have some big decisions to make." The Vikings also have an eye on a roster cutdown from 90 to 80 on Tuesday. Joe Webb will be the No. 2 quarterback in this game, but that battle will continue into the final preseason game as either he or Christian Ponder is likely to get the start while Donovan McNabb rests.

4, Can Herrera hold up?

Right guard Anthony Herrera is angry with reporters because we've wondered whether a guy nine months removed from tearing an ACL can be ready for the start of the season. But it's nothing his own coaches aren't wondering as well. And, besides, it's the coaches who declared the position up for grabs when training camp started. If Herrera is able to hold up without suffering any setbacks, it will go a long way toward stabilizing the offensive line. Now is not the time to be thinking of ways to upgrade the right guard position. That can come in the offseason. Now is the time for the Vikings to hope for the simple continuity of having Herrera back as a starter.

5, Kevin Williams' backups.