EDEN PRAIRIE, Minn. (AP) — Through their first two preseason games, the best performance from Minnesota's first-team offense has been by rookie punter Jeff Locke.

The Vikings haven't done much well in these exhibition games yet. Each incompletion by Christian Ponder or three-and-out series by the unit has only heightened concerns whether this team can be balanced enough to build off last year's playoff appearance.

Even when the wins and losses don't matter, decent showings will somewhat appease the fans, soften the skepticism of the analysts, and most importantly give the coaches and players confidence in a chemistry carry-over to the regular season.

"Yeah, there would be some reason for concern if we don't do certain things that we've set out to get accomplished in this ballgame, or any ballgame," coach Leslie Frazier said on Wednesday.

The Vikings are at San Francisco on Sunday, and most of the starters are expected to play into the third quarter. But before this becomes an anxiety-raising, must-thrive event, there's a critical fact to point out about the way the offense bumbled through the first two games.

"I was coming off the sideline saying, 'Oh, my gosh, what are we doing?'" wide receiver Greg Jennings said. "Like, we were struggling. And then I saw this guy on the sideline that had this '28' jersey on, and he wasn't dressed, and I'm like 'Oh, yeah. I forgot. We don't have a big part of our offense out here that draws a lot of attention.' So this week will be a lot better."

Assessing a team without the league's rushing leader and Most Valuable Player is hardly worth it, especially considering the way the Vikings revolve around their star running back Adrian Peterson. This week against the 49ers, the plan is for Peterson to be on the field.

"If you're an offensive player, we definitely want to take some steps forward," Peterson said.

The Vikings have averaged only 14 first downs and 276 yards over the first two games, though that includes all of the time logged by backups and long shots trying to make the team. Ponder is 6 for 14 for 68 yards and one interception. His passer rating is 28.3.

So this next exhibition will be a valuable opportunity for Ponder to continue trying to establish a rhythm with Jennings, rookie Cordarrelle Patterson and the rest of his receivers. Don't expect a polished product either, Jennings said.

"Kinks will never completely be ironed out," he said. "There will always be a new wrinkle that we put in that we're going to be trying to perfect. Just our relationship, our chemistry, we're going to try to perfect that forever."

NOTES: The finalists for the punt returner role are incumbent Marcus Sherels and fellow CB Bobby Felder, according to special teams coordinator Mike Priefer. The Vikings have been grooming Patterson for that job, too, but they're trying to narrow his focus for now. ... DT Sharrif Floyd's minor left knee operation went fine, Frazier said, and he's expected to be ready for the first week of the regular season. ... In addition to Floyd and FB Jerome Felton, who's out for the rest of August recovering from an appendectomy, the only other significant player held out of practice Wednesday was WR Jarius Wright (concussion symptoms).