The Vikings take the stage Saturday night at Arrowhead Stadium for their third preseason game, which for NFL teams is typically the one that carries the most weight.

There will be butterflies for some players during this so-called dress rehearsal. But by all accounts, the Vikings don’t plan to treat this performance much differently than their first and second.

Sure, their scout team pulled on yellow jerseys late in the week to simulate such Kansas City Chiefs standouts as Tamba Hali and Eric Berry, but head coach Mike Zimmer said the game-planning was minimal.

The offense and defense have practiced pretty much everything in their playbooks, but that doesn’t mean they plan on putting it all on tape for the St. Louis Rams and the rest of the NFL to see.

And while the starters are expected to play at least one half, that wouldn’t be much of a departure from their game a week ago, when quarterback Matt Cassel and most of the starters got the hook at halftime.

“This is still a lot about us,” Zimmer said. “It’s still about what we do. We’ll have plenty of time to prepare for St. Louis when we get going in there. It’s more about the routine that we are going to do this week, so we get into the in-season schedule routine as opposed to really sitting down and game-planning.”

Still, even if Zimmer says the Vikings are treating Saturday’s exhibition as if it is just another warm-up before the regular season’s opening act, several players will continue to audition for leading roles, starting with the all-important decision at quarterback.

Picking the passer

Yes, Teddy Bridgewater looked good in carving up the Arizona Cardinals’ backups. And of course his preseason stat line would look good for any QB, let alone a rookie.

But barring an injury or a Douglas-vs.-Tyson-type upset, Cassel — whose 122.3 passer rating is even better than Bridgewater’s 106.4 — will be the starter in Week 1. Zimmer just hasn’t announced it yet.

Since the end of spring workouts two months ago, he has had a date in mind for when he would like to name a starter, but he is not sharing that date with anyone.

“At this point, it’s just going to be one of those things where we just wait and see,” Cassel said. “Coach will make that ultimate decision. At the end of the day, I’m going to continue to prepare and do what I need to do to get ready for the season. And then when the time comes and coach tells us, then that’s what we’ll have to deal with.”

The safety dance

If the competition at quarterback is the clearest, the battle at safety is the most confounding. The Vikings have auditioned a handful of safeties next to starter Harrison Smith, who seems poised to take a step forward under Zimmer. But injuries have made it hard for Zimmer to get a clear evaluation of some of them. And the fact that he brought in old buddy Chris Crocker was a sign that the healthy ones have not impressed.

Crocker, Kurt Coleman and Robert Blanton, who returned from a hamstring injury this week, have gotten most of the reps with the first-team defense. Meanwhile, Jamarca Sanford, who was the starter next to Smith in 2012 and 2013, seems to be an afterthought.

“We’re still trying to look at all of them,” Zimmer said. “Blanton will get a lot of time this week, because I haven’t seen him yet. We’ll give him a lot of plays. The rest of them, we are going to try and split up the time the best we can.”

Caught in the middle

Veteran Jasper Brinkley, who is back after a lost year in the desert playing for the Cardinals, has the edge on youngster Audie Cole in the battle to start at middle linebacker between Chad Greenway and rookie Anthony Barr.

“Jasper seems to be a little bit more communicative, and Audie seems to have a little more range,” Zimmer said. “As far as the running game, they are very close and in the passing game, they are similar.”

But the fact that neither is trusted enough to play on passing downs suggests that the Vikings lack an ideal option.

Magic number: 3

One can easily make the case that the competition to be the team’s third cornerback is much more significant than the one at middle linebacker. NFL offenses lined up with three or more wide receivers on more than half of their plays last season, and that figure could surpass 60 percent in 2014.

The Vikings believe they are in good shape with Xavier Rhodes and Captain Munnerlyn. But they can’t feel all that comfortable with their third cornerback. Josh Robinson has been in and out of practice with a hamstring injury. Rookie Jabari Price is now injured after opening eyes in training camp. And reclamation project Derek Cox hasn’t been able to climb the depth chart.

Robinson, who could make his preseason debut, remains the front-runner, but this competition is far from over.

“We’re going to be competing all of the way through this preseason,” defensive coordinator George Edwards said. “Especially in some of those positions that we have had a tighter competition and we’ve had some injuries throughout camp, this is a time for those guys to get back out there. We need to see where they are.”