Don’t expect Kyle Shanahan’s much-discussed offensive genius to be on display when he makes his head-coaching debut Friday night.

Shanahan not only isn’t game planning for the 49ers’ preseason opener in Kansas City, he isn’t planning to call any non-vanilla plays.

I’m “very well aware,” Shanahan said, “that any play that works in the preseason will not work in the regular season.”

The game might not gauge Shanahan’s ability to juggle head-coach duties and pick plays, but it could offer a bit more insight into his ability to pick quarterbacks.

Rookie C.J. Beathard, the first offensive player drafted in the Shanahan era, will make his debut four months after the 49ers traded up to select him in the third round. Beathard was unusual — he was the first QB the 49ers selected with a top-200 pick since Colin Kaepernick in 2011 — and mildly surprising: NFL Network draft analyst Mike Mayock said most teams viewed Beathard as a sixth-round selection.

Shanahan didn’t see it that way. And after Beathard’s bumpy start to training camp, it’s becoming easier to see why the 49ers didn’t follow the herd.

On Wednesday, Beathard strung together a sweet series of throws in practice. He began by heaving a perfectly placed rocket that was dropped by wideout Victor Bolden Jr. after he it traveled about 60 yards in the air. He later ripped a deep, over-the-middle strike to Trent Taylor, and threaded a completion to Kendrick Bourne, who was surrounded by three defenders.

Yes, it was a practice, the 49ers’ first without pads, but it was also a contrast to Beathard’s earlier offerings. During early camp practices, his deep balls often fluttered and some other throws were downright puzzling. On July 30, during the 49ers’ first padded practice, he rolled left, spotted all-alone running back Raheem Mostert standing a few yards in front of him and … sailed a pass comically off target.

Beathard, whose football-junkie spirit was part of the attraction for Shanahan, was asked how he dealt with his initial summer struggles.

“When you’re a rookie, you’re not going to be perfect,” Beathard said. “You know there’s going to be plays where you mess up. Forget things. … But as you continue getting better with more reps, the easier it comes. And that’s how it’s been going.”

Indeed, Beathard began camp as a third-stringer, but he’s now sharing second-team snaps with Matt Barkley behind unquestioned starter Brian Hoyer. Shanahan has said Barkley will be the first quarterback off the bench in Kansas City, but the depth chart could look different for the second preseason game.

On Friday, Beathard will play his first game since his ugly performance in Iowa’s 30-3 loss to the Florida in the Outback Bowl capped a disappointing senior season. He completed 7 of 23 passes for 55 yards with three interceptions in that game to cement his sixth-round status in the estimation of many NFL evaluators: Beathard had a better completion percentage (61.6 to 56.5), more passing yards (2,809 to 1,929) and a better TD-to-INT ratio (17-5 to 17-10) as a junior than as a senior.

Beathard has credited Shanahan for his gradual early progress. During practice, Shanahan stands behind the offense and thinks like a quarterback.

“As the ball’s snapped, he goes through every play as if he was sitting back there at quarterback,” Beathard said. “He puts himself in that situation. … So it’s nice to ask him what he thought; where he would have gone on certain plays. So you can try to replicate his thought process as much as possible.”

Four months ago, the selection of Beathard shed light on Shanahan’s thought process when it comes to quarterbacks. On Friday, the long process of determining if Shanahan was right will begin.

Eric Branch is a San Francisco Chronicle staff writer. Email: ebranch@sfchronicle.com Twitter: @Eric_Branch

Friday’s game

Who: 49ers vs. Chiefs

Where: Kansas City

When: 6 p.m.

TV/Radio: Channel: 5 Channel: 13 Channel: 46/810, 107.7

5 players to watch

RB Matt Breida: The undrafted rookie from Georgia Southern has looked more decisive — and impressive — than fourth-round pick Joe Williams this summer.

LB Reuben Foster: The first-round selection has been dealing with a balky left ankle, but he’s expected to make his NFL debut after having four interceptions in camp.

DT Solomon Thomas: The No. 3 pick hasn’t unseated Tank Carradine for a starting spot … yet.

S Lorenzo Jerome: The undrafted rookie’s unafraid, instinctual play has made defensive coordinator Robert Saleh a bit nervous, but he hasn’t been beat often in coverage.

WR Trent Taylor: The fifth-round pick has followed a 136-catch senior season by grabbing just about everything in his area code in camp.

— Eric Branch

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