Vikings at Seahawks: Five things to watch, including Vikings' offensive rhythm

The Vikings travel to Seattle for their second preseason game on Friday night, making their final trip out of Minnesota until Sept. 17. Here are five things to watch in their matchup with the Seahawks:

How the first-team offense looks: Coach Mike Zimmer made it clear this week he wants to see the Vikings' top offensive unit get into a rhythm in this game, and the group will test its luck on the road against one of the league's best defenses. Zimmer hinted the matchup with the Seahawks could be an opportunity to take a look at younger players against better competition. If the Vikings' top offense is able to take the ball and score on its first drive, after sputtering last week against Buffalo, it could earn itself a shorter night's work.

A test for rookie receivers: Stacy Coley stood out with three catches for 67 yards against the Bills. But this week could be a step up in class for Coley, especially if he gets any work against Seattle's first-team defense. The same goes for fellow rookie Rodney Adams, who caught a pair of passes for 12 yards and a touchdown against the Bills.

Wilson could stress defense: Asked Wednesday about the toughest quarterbacks he's faced, Zimmer said, "The guys that can move are always going to cause you trouble." That's certainly true of Seahawks quarterback Russell Wilson, who could test the Vikings' pass rush discipline with his ability to make plays outside the pocket. Zimmer wants his rushers to pursue Wilson without getting behind him or creating open lanes for the quarterback to scramble. Wilson's ability is also a good test for some of the Vikings' young corners. "It changes coverages a lot, because you may have to account for the quarterback," Zimmer said. "You might get a lot more one-on-ones outside."

How many injured starters return? The Vikings have remained cautious with left tackle Riley Reiff and running back Latavius Murray. Left guard Alex Boone also missed the team's final three practices of the week, and cornerback Trae Waynes hasn't practiced since injuring his shoulder early against the Bills. Safety Andrew Sendejo, wide receiver Laquon Treadwell and linebacker Kentrell Brothers could all sit out or see limited playing time because of injuries as well. There's still no reason for the Vikings to rush any of their injured players back, so they'll likely continue to be cautious with some of their injured starters, given the fact they have nine days between the Seahawks game and their third preseason game at home against the 49ers.

Offensive line looking to provide better protection: The Vikings offense stalled because of two sacks and a holding penalty while the first-team group was on the field last week in Buffalo. Even with injuries still likely forcing the Vikings to mix up their personnel, they'll hope for a more consistent showing against the Seahawks. Zimmer said he liked the idea of playing in a loud environment against a formidable defense in the preseason, and the Vikings will get the chance to see how well they can do protecting their quarterbacks (particularly Sam Bradford) against Seattle's pass rush. After the Vikings' game in Seattle, they have two home preseason games and the regular-season opener at U.S. Bank Stadium against the Saints before they head back out on the road. Considering their next trip away from home is in Pittsburgh, it would serve the Vikings well for their offensive line to have a good showing Friday night in Seattle.